73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Stewart G Griffin on January 03, 2010, 02:58:51 pm
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Ok, so as you may know, i sucessfully helicoiled (my first time) one of the starter bolt holes on the engine.
Of course, in order to this you must first take the starter off and then when you're done, put the starter back in (arms still aching).
The only things i did before the truck now doesn't crank(you guessed it) were:
a) disconnect the battery negative cable----for safety.
b) take the starter out.
c) put the starter back in.
d) reconnect battery.
i know the battery is good because i tested it, and also i took the battery out of the cavalier and still no crank. So, the battery is not the problem. i'm getting all gauge lights etc.
i also know i got the wiring to starter right-----positive cable from battery and the two red wires with the fusable links the merge into and "O" ring go on the big terminal. And then the remaining wire goes tot the "S" terminal.
Also note that it is 27F outside (just coincidence that i finally have time to work on the truck due to work and other bs that cropped up) but i don't think this has much to do with the no crank situation.
What i'm proposing is that we do a very basic, step-by-step, analysis and plan of action that an Automotively Developmentally Disabled person such as myself can understand and follow. Remember to use detail and language that a 4 year old can understand.
NOTES:
1) If the term ADD offends, i will stop immediately. We would need to come up with another self-deprecating term to describe individuals such as myself (and possibly to encourage persons like myself to become more knowledgable about cars).
2) i was going to use the term AR, automotively retarded, but i thought that this would probably be offensive.
3) The only other thing was i noticed that the ground wire coming from the battery negative cable and bolts to the radiator core support is crunchy and brittle and the plastic is bubbly and some of it is gone and the wires are exposed and i know it was not like this before. Also, when i got the truck running last summer with the new (305) mill, i noticed that there was smoke comming from underneath the hood during times of greater than normal cranking times. i did not know what this was and wasn't concerned at the time, only concerned about getting the truck running. i will describe this in much greater detail as well as provide pics later.
4) In the meantime i will use my fleplate turning tool to see if the engine seized up which i really doubt it did.
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Hmmm. Have you tried tapping the starter lightly with a hammer? If their going bad, they'll sometimes have a "dead" spot and you can tap it and it'll crank. Check your connections, too. Maybe a little grease got on your connection.
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So anyways, here is the small wire i'm talking about:
(http://i223.photobucket.com/albums/dd31/sencraig/019.jpg)
It branches off from the main battery negative cable Figs 2, 3:
(http://i223.photobucket.com/albums/dd31/sencraig/015.jpg)
(http://i223.photobucket.com/albums/dd31/sencraig/014.jpg)
Note that there is no electrical tape on that wire----the plastic, apparently burned/melted off. What would cause this?
i am working on a diagram, until then:
--the main battery negative goes to the alternator bracket
--all the wires are basically supposed to be where they were originally as stock---even the steel braided looking one from the firewall is present and attached to the back of the cyl head.
--i did notice some "smoke" coming from the hood when i first swapped in the 305 during heavy cranking, apparently this was it? The only things different that i'm not using now that i did with the previous 350 engine setup are electric choke and the idle comphensator thing, but these wouldn't really cause the problem?
The engine turns easily as expected, so we know the engine didn't seize up.
Everything wiring wise is pretty much stock 83. This is one thing i'm proud of and happy that the previous owner didn't hack up which is oh so common for some reason.
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That melted ground wire is a fire waiting to erupt. The smoke you saw was probably that wire melting from excessively heavy current passing through a wire too small for the current draw. Where does it connect to? Replace that thing ASAP. I would also scrape away the paint under that 'star' washer which is acting as a ground on your core support. I did this to all of my ground points when I bought my truck and I saw over 0.5 volt improvement at my amp guage and my lights were brighter. Also, it's never a bad thing to install a battery to frame (not core support, but the actual frame) heavy ground cable. I suggest 4 AWG wire.
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Yes, this wire DOES concern me and i'm not going to do anything else until this matter is taken care of. The starter problem can wait.
This wire branches off from the main, large battery negative cable. (second pic) The batt negative cable itself goes directly to the alternator bracket. (like i said, i am working on a diagram and it should be up shortly). i've been doing some reading and most likely the large, main batt negative cable IS NOT grounding properly to the alternator bracket, which is why the small wire is getting overloaded and burning up, so i've got to check that.
i'm thinking during the engine swap i reconnected this wire to the alt bracket improperly (put washers in wrong order or something) or maybe the wire iself is bad.
P.S. why did the factory use star washers anyway?
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Your big wire is on the alt bracket, right? Scratch the paint off that bracket and see if theres corrosion on the bolt/ washer. I think I moved my wire to the intake manifold, but I put a serpentine kit on.
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Make sure the alt bracket is grounded good. I had the same thing happen on mine and it turned out to be a bad battery cable. I cleaned all the connections and they were good, but the cable inside was all black corroded and it had enough wire strands still attatched to look good to the voltmeter, but it didn't have enough strands to move the current through it. If you don't have one now, get a star washer for it, they help.
Put an ohm meter on the negative cable from end to end and twist and move the cable while it's hooked to the meter and see if the readings change. if they do, the cables bad.
I'd go through and clean the connections. If a connection shows bad on a voltmeter, it's bad. If a connection shows good on a voltmeter, it may still be bad.
Since it burned up the smalll wire, check your ground strap to the engine too. The ground strap goes from the very back end of the passenger side head to the cab.
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Your big wire is on the alt bracket, right? Scratch the paint off that bracket and see if theres corrosion on the bolt/ washer. I think I moved my wire to the intake manifold, but I put a serpentine kit on.
Everything looks just fine, no corrosion.
But this leads me to my next questions.........
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Make sure the alt bracket is grounded good. I had the same thing happen on mine and it turned out to be a bad battery cable. I cleaned all the connections and they were good, but the cable inside was all black corroded and it had enough wire strands still attatched to look good to the voltmeter, but it didn't have enough strands to move the current through it. If you don't have one now, get a star washer for it, they help.
Put an ohm meter on the negative cable from end to end and twist and move the cable while it's hooked to the meter and see if the readings change. if they do, the cables bad.
I'd go through and clean the connections. If a connection shows bad on a voltmeter, it's bad. If a connection shows good on a voltmeter, it may still be bad.
Since it burned up the smalll wire, check your ground strap to the engine too. The ground strap goes from the very back end of the passenger side head to the cab.
1) The ground strap is present, tight and appears "good", but how do we check it?
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Yes, this wire DOES concern me and i'm not going to do anything else until this matter is taken care of. The starter problem can wait.
This wire branches off from the main, large battery negative cable. (second pic) The batt negative cable itself goes directly to the alternator bracket. (like i said, i am working on a diagram and it should be up shortly). i've been doing some reading and most likely the large, main batt negative cable IS NOT grounding properly to the alternator bracket, which is why the small wire is getting overloaded and burning up, so i've got to check that.
i'm thinking during the engine swap i reconnected this wire to the alt bracket improperly (put washers in wrong order or something) or maybe the wire iself is bad.
P.S. why did the factory use star washers anyway?
I don't like the big ground wire for the battery going straight to the alternator bracket. That means ground to the frame is going through the ground strap for the motor which might not be that great and any bolts that touch motor or transmission to frame like the motor mounts or tranny mounts. Ground is being accomplished but you should re-mount that ground from the battery directly to the frame.
This is my battery to frame ground:
(http://memimage.cardomain.com/ride_images/1/1232/2641/3078820222_large.jpg)
I scraped the paint off under where the bolt holds the terminal down and then I shot it with black Krylon afterwards.
The factory used those star washers as far as I know so that they bite into the metal and actually give a decent (sort of) ground.
I've also had a battery (positive) cable disintegrate from the inside and looked fine on the outside. I'd get intermittent starting capablities until I cut the terminal end off and found the copper strands inside were entirely corroded.
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I suspect the wire from battery negative to the alternator bracket as mentioned before. Most likely where it connects to the bracket it is loose or corroded. Sometimes the crimp connector there may loose its hold as well. Wiggle and pull lightly on the wire where it goes into the crimp connector at the bracket and see if its loose or wants to come out. Take the screw out of the alternator bracket and get to bare metal there using emery cloth or whatever you can get your hands on to remove rust/corrosion, etc. Also clean the connections at the battery. In one of your pics there appears to be rust on the battery positive. I assume that both of the battery cable terminals are rusty and that could be the problem. This sounds dumb, but I'll ask anyway: Is that sticker on your battery covering part of the negative connection under the terminal?
SUX2BU99: why would you ground the frame instead of the alternator bracket? The starter motor is the biggest current draw and its attached to the motor, not the frame??? Seems like attaching to the frame requires the current to pass through the frame and then into the motor through ground straps that weren't designed to carry that kind of load. The alternator bracket seems like the perfect spot (apparently GM agrees). If you wanted to add a second wire to the frame I could see that, but I'm confused.
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i'll address the whole alt bracket vs. frame vs. engine block as ground thing in a sec, but first:
Make sure the alt bracket is grounded good. I had the same thing happen on mine and it turned out to be a bad battery cable. I cleaned all the connections and they were good, but the cable inside was all black corroded and it had enough wire strands still attatched to look good to the voltmeter, but it didn't have enough strands to move the current through it. If you don't have one now, get a star washer for it, they help.
Put an ohm meter on the negative cable from end to end and twist and move the cable while it's hooked to the meter and see if the readings change. if they do, the cables bad.
I'd go through and clean the connections. If a connection shows bad on a voltmeter, it's bad. If a connection shows good on a voltmeter, it may still be bad.
Since it burned up the smalll wire, check your ground strap to the engine too. The ground strap goes from the very back end of the passenger side head to the cab.
First off, i got this multimeter because i couldn't find the other one that i had:
(http://i223.photobucket.com/albums/dd31/sencraig/416VBJ14E8L__SS500_.jpg)
i don't know how to use it----the instructions are not that helpful.
1) i understand the theory behind testing the battery negative cable, but:
a) Where, exactly, do i put the leads on the battery cable?
b) Which dial setting to use and why?
1.5) How would you test if the alternator bracket is grounded good?
2) the crimp connection is good and no the sticker is not covering any of the terminals.
We need to kind of slow it down; i'm AC, automotively challenged. Remember?
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Nothing will work without ground. Poor ground = poor/intermittent operation. It's also an efficiency thing - your electrical system will have to overcome less resistance when you use wire of ample size and with solid/clean connections.
For some reason, that small wire going to the radiator support is acting as your biggest ground. Anything metal will act as a ground, but the "ground" must be big enough to handle the current draw, and this includes the ground wiring. You can be redundant here without causing harm. I would connect a new ground wire to the Alternator bracket, and another to the frame, and yet another from the motor to the frame. The motor, theoretically, is electrically isolated from the frame by the rubber motor mounts.
I know you're on a very limited budget, but these wires are cheap and can be found anywhere, even at Walmart. Get some new wire for the 3 locations I mentioned above and when in doubt get a bigger gauge than you think you need. Scrape all of the connection locations down to bare metal and connect securely with a nut/bot/lock washer combo (a star washer is also acceptable). Then paint over to prevent rust. Route all of your wires away from sources of heat, and secure them with hold-downs or cover with wire loom to avoid chafing (more of a concern for the positive cable).
Electrical problem can torch a vehicle, and with high-amp applications like the starter and alternator, go with new wire and save yourself the headaches. Even if it is a starter problem, that melted ground wire is a huge concern.
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SUX2BU99: why would you ground the frame instead of the alternator bracket? The starter motor is the biggest current draw and its attached to the motor, not the frame??? Seems like attaching to the frame requires the current to pass through the frame and then into the motor through ground straps that weren't designed to carry that kind of load. The alternator bracket seems like the perfect spot (apparently GM agrees). If you wanted to add a second wire to the frame I could see that, but I'm confused.
You raise a good point; one that I had overlooked. On my truck, I have a chrome alternator bracket so I never have had a battery to alt bracket ground. In this rather old pic of my motor, you can see I have a wide braided engine-frame ground strap:
(http://memimage.cardomain.com/ride_images/1/1232/2641/3078820202_large.jpg)
I prefer grounding to frame when I can. My engine is to the frame and so too is my battery. I'm not saying the alt bracket is necessarily a bad place to ground in general, just so long as there is good metal to metal contact without paint (or rubber like on the motor mounts) getting in between and a wire of at least 8 AWG in size for short runs. Something is causing that smaller wire to melt.
Stew, do you have an engine to frame ground? What smitty77 said might sound like overkill on the grounding points but it's cheap insurance.
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(http://i160.photobucket.com/albums/t195/wes2880/Tools/416VBJ14E8L__SS500_.jpg)
To check for resistance, bad connections set the meter to the setting the blue line goes to. That checks for OHMs. once you have it set there touch the two leads together, the readout should go to 0.000 or real close to it. this is your baseline reading. now put one lead on the alternator bracket and put one lead on the engine block. make sure they are making good contact in both places. now the readout should read the same or very close to what it read when you simply touched the leads to each other. if the number is higher, there's resistance there. resistance can either come from bad connections, corrosion, or the leads aren't making good contact.
You can check all your grounds like this: connect or touch one lead to where the main battery cable goes, and touch the other lead to whatever ground you suspect. the reading should be the same or very close to when you touch the leads to each other.
When you check a wire/cable, attach one lead of the meter to each end of the cable you want to test. for example on the main bettery cable, you would put one lead on the alternator bracket end, and one on the part that bolts to the battery. then while they're connected, wiggle and twist on the wire and see if the OHM readout changes. If the readings change and it's not because of movement in the end leads, you have a bad cable. sometimes cables corrode inside or can mechanically break from 20+ years of the engine moving and flexing that cable back and forth.
If you do connect the main battery cable to the frame instead of on the engine somewhere, all the battery cranking power will have to go through the ground strap. Remember the engine/trans are isolated from the frame by the rubber engine mounts and the only real connection to the cab/frame is the ground strap and maybe the shift linkage.
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quote, "stew do you have an engine to frame ground etc....."
i don't think i have an eng-to-frame ground, but i will check. Where would this be on a 83 stocker? i know i have the cyl head to firewall small braided wire, but this doesn't count?
The other thing i noticed, and if anyone can provide a picture of a completely stock setup this would be greatly appreciated, is that looking at a picture of a presumably stock setup, there is a star washer underneath where the big main batt cable bolts to the alternator bracket. i don't have a star washer on mine and it wouldn't suprise me if something this simple could be the culprit, but we'll see.
2) will check all connections using the multimeter; i kind of figured to use the 20 DCV when testing the battery from watching some online videos, but why the 2000/funny, i'm assuming, ohm symbol when checking resistance, grounds etc.?
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quote, "stew do you have an engine to frame ground etc....."
i don't think i have an eng-to-frame ground, but i will check. Where would this be on a 83 stocker? i know i have the cyl head to firewall small braided wire, but this doesn't count?
The other thing i noticed, and if anyone can provide a picture of a completely stock setup this would be greatly appreciated, is that looking at a picture of a presumably stock setup, there is a star washer underneath where the big main batt cable bolts to the alternator bracket. i don't have a star washer on mine and it wouldn't suprise me if something this simple could be the culprit, but we'll see.
2) will check all connections using the multimeter; i kind of figured to use the 20 DCV when testing the battery from watching some online videos, but why the 2000/funny, i'm assuming, ohm symbol when checking resistance, grounds etc.?
I'm not sure if they came with that star washer, but I think so. If I had one that it was missing on, I always added one.
2 - Actually you can use any of the selections for OHMs. I use around 2000 I think because it seems to be a good sensitivity to me. If you choose 200 it will still work, just won't be as sensitive. If you use 2000k it will be way sensitive and you'll have a hard time telling whats bad and whats not. try all the different settings and see what you think. it's all preference.
It's kind of like the DCV settings. if you set it to 200V it will show whole numbers (like showing 12V instead of 12.4V) so to get the x.xx numbers you have to set it to 20V.
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(NOTE: i've been "reassigned" to 3rd shift so hopefully the pattern will work like this---work and report on the truck from noon to about 4,5,6ish. Hopefully, this can be consistent)
1) So what happened as far as the main negative cable is concerned is i took it off the truck, put the dial on the multimeter to 2000ohm and put the leads at the opposite ends of the cables and basically got a 0 reading even when moving the cable around. i also experimented with different dial ohm settings and pretty much 0 except for the 2000K setting but that's probably too high?
i also did this with the smaller branched out cable and also got 0 reading.
i'm not sure what this means.
Also note that i used the very tips of the leads when touching the cables because i think this gives a more consistent reading? i noticed that if you use the side of the leads and if you move them around the reading changes. So, by using the tips only when moving the cables around this would help determine if in fact the cable is bad or is it because the surface area of contact by the lead is changing?
2) As far as alternator bracket grounding, i put a lead on the bracket and then tried putting a lead on the block but the meter read 1 and stayed that way even on different dial settings. Then bracket and exhaust manifold and still reads 1--no change on the meter.
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A reading of zero or close to it is good. OL- out of limits means its broke somewhere
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Put it on the 200 setting when checking resistance in wires. The resistance should be a fraction of an ohm (meaning very little resistance to pass current, which is what a properly functioning cable should do). You should get a reading of something less than 0.10 ohms, but certainly less than 1.0 ohms.
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Ohming out a battery cable is a waste of time. The only "good" way to find resistance in a battery cable is by voltage drop testing. I can elbarote in
great detail
on how to do this if you wish later but as far as your no crank condition...
1)Make sure the truck is in park....try to start... Then try Neutral
2)Take your test light to ground and touch the S terminal. Have an assistant crank the engine. See if it lights up.
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1) will try neutral start,
but just out of a hunch i don't think the Neutral safety switch is the problem..... Actually, this is not good diagnostic strategy. Shame on me. Never go on hunches, never ASSume anything.
2) i don't want to involve anyone else so, i do have a remote starter thing; Is there a way to use/wire this w/out starting the engine/damaging anything? In other words, ability to crank but not start the engine?
Actually, this is stupid too; we need to know if power is coming from this wire; Using a remote starter would not tell us this. So, i need to involve another person. (?)
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OK, i tried #1 that you presrcibed and the truck actually started up and ran for a few secs and i didn't even have to pump it in this cold weather(because i just wanted to see if it would crank not run so i didn't pump it) and i'll discuss all this more in sec.
i unhooked the small branch ground wire that goes to the radiator support to see if i could isolatethe problem to the large main wire. When i did this, no lights, no cranking, no dash lights nothing.
i also noticed simultaneously that the bolt on top on the alternator bracket the bolts down this large main negative from battery wire is basically stripped (sounds like a familiar theme?) and basically you can't get it real tight---it will just screw in to barely snug and then pop out.
So, i fiddled around with it to try to get it tight enough to ground and yes, it can if you get it just right, but then after the vibration of the engine starting and then stopping it lost ground, so i think i may have isolated the problem. (the smaller wire was still unconnected).
i will probably continue more on the problem tommorrow as i have to go to work. And working 3rd shift is better than working no shift.
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Put the long alternator bolt through the eyelet on the negative cable and bolt it there.
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i unhooked the small branch ground wire that goes to the radiator support to see if i could isolatethe problem to the large main wire. When i did this, no lights, no cranking, no dash lights nothing.
i also noticed simultaneously that the bolt on top on the alternator bracket the bolts down this large main negative from battery wire is basically stripped (sounds like a familiar theme?) and basically you can't get it real tight...
Then I would say you've isolated your problem. As we suspected, that little wire was serving as the entire path to ground when things got shaking enough to pop loose that large cable to the alt bracket. While you're replacing that bolt on the alt-bracket, scrape the paint off the bracket where the wire mates to it and clean it up good before your re-attach everything.
Nice work Stewart!
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Ground to the engine, not the frame - as your biggest draw is the starter motor. Run a heavy wire - 4 or 8 ga. to the the cab and rad support and frame. If it is not starting verify that the purple wire is on S and not I. That would cause it not to start.
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Yes, i got the wiring right--the starter will turn over provided i can get good ground.
Anyways, the next step is to rebuild or get a new cable. As you can see from the above pictures #2 and 3, that smaller branch wire's outer jacket is toasted and i feel it would be unnessesarily risky to re-use this cable.
i'm not opposed to building my own replacement, but i figured it would be easier to try to get a stock replacement.
a) This cable is apparently discontined by GM as i found out at the dealer. (more "old GM, new GM" horse manure)
b) Prestolite, which i think is top quality, has a pre-made application available, but who carries prestolite?
c) Year one has new GM cables in stock for $23.
d) Other suggestions as far as custom/do it yourself ideas?
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i had bought a new ground cable at advanced, and it had that core support ground cable built in. i did have to extend it 6" to reach the core support, but it is working just fine.
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i will try advance soon. i do have some aftermarket autoparts store type cables which i used for the test stand.
What i'm mainly concerned about as far as building my own is where/how the small branch connection is connected to the main terminal:
(http://i223.photobucket.com/albums/dd31/sencraig/010.jpg)
---the auxillary ground wires on the aftermarket are smaller than on the stock setup. i feel this is not a good thing, so this is why i'm asking how this connection is made so i can make a new one with a larger gage wire.
--- Could i just make an auxillary ground wire with and "O" terminal and just sandwich it between the main cable end and the battery terminal?
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The wire on the cable is fine.
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So these auxillary wires are like 8 gauge or something?