Jump start oops

[velojym]

I just did my fusible links, or should I say put some in where they were supposed to be.  You can reach down and take the large and small nuts off the starter solenoid without removing anything.  If you don't have long arms like me you might crawl underneath and do it.  If you really want to get the wires up close to you then you can take the connections loose from the alternator, but its not necessary.

My wife jokes about my long arms, but my problem here seems to be my rather large hands. I'll have another look tomorrow, see if I can find another way in.

[VileZambonie]

Diagram and gauge

[velojym]

Ok. I know there's power to the junction block, so the three things I'm worried about are the known bad battery, the fusible link from the alternator to the starter, and possibly the alternator itself.

One question, though... if the HEI requires power to run the engine, and if that wire from the alternator is bad... as well as the battery, what's running the ignition?

Our airplane magnetos can be a bit persnickety at times, but they'll go on running with no help from the battery or charging system.

[Grim 82]

If you drop the starter you should have enough slack in the wires to lower it down and have good access to the connections. I would definitely track down the current problem before you pull the engine. You'll want to have a clean slate before you open up another can of worms.

[velojym]

I agree, and I'm hoping most of the hack-job can be corrected when I pull the engine. I still want the truck running up until that time, though.

[Irish_Alley]

I may have missed it but just some questions. Did you check the battery with it fully charged? Also a "good" battery can't run a truck for long especial with the headlights on. A good alternator will keep the truck running till you shut it off. Did you test the output post on the alternator to see what its putting out when the truck is running? Or what its at when the truck key is on. If I miss something im sorry but I don't think I saw this.

[velojym]

I'll have to get him while he's home to borrow the tester again, but after a day or so of charging, I got it turning over snappy again. Then, after I got home this evening, I bumped the key just a bit, and it sounded like it had plenty of oomph.
I think my multimeter has a problem, possibly a break in one of the leads, so it's been less than useful through this. There's a cheap little one somewhere in the basement, and I'll see if I can find it to work on Earl, and to test the big meter's leads.

The voltage gauge on the instrument panel was reading about 12v the whole time, before, during, and after I ran the engine. It read the same later when I bumped the key.

Since I didn't have a working meter, I used a screwdriver to ensure that I at least had a field, and it did.

I just finished putting together a fusible link, leaving the 10ga side long so I don't have to make two of 'em. I'll run it directly from the alternator to the battery. If that does the trick, I'll know to go ahead and replace the wire to the starter. Everything I see says this will work just fine, unless there's something I'm overlooking.

[1980c10]

When your truck is running you should have about 13.8 volts. If your voltake does not increase after the truck is running you have an alt problem or possibly a wiring issue.

[velojym]

When your truck is running you should have about 13.8 volts. If your voltake does not increase after the truck is running you have an alt problem or possibly a wiring issue.

That's what I'm chasing right now... or when I can get a little time. I'm gonna wire the alternator to the battery to see if I get a charge that way. If that takes care of it, I'll re-route that wire to the starter and be done with it... at least until I'm able to pull the engine and fix 'er up right.

[VileZambonie]

So you are going to run a direct bypass around all of your circuit protection?

[velojym]

That's what I've been trying to find out. As far as I can get from anyone, including the manual, is that there's a fusible link on the line running to the starter... then the main positive cable back to the battery.
The wire I put together last night has a fusible link in it, so it would seem to offer the same protection the truck would have had if it were properly wired.
I did mention before that the P.O. dropped the engine in and just twisted together a lot of the wires, no solder nor any sort of protection at all.

[1980c10]

Don't take this the wrong way; you are making this harder than it has to be. Just test voltage at the back of the alt and ground for 13.8 volts if you don't have it replace the alt. If you have 13.8 at there and not the battery then replace the wire from the alt to the starter with the fusible link installed inline.
No need to wait until you pull the engine. Also you don't need to pull the engine to make repairs to the wire harness. I removed my entire wire harness to make the changes I wanted and reinstalled it when I was done. Its easy to just unplug untie and unbolt and pull it out.  There is no better way to inspect it and know where you are really at than to lay it out on your workbench.
If you really want to run a wire from the alt to the battery to see if it charges the battery per your gauge. Just hook up one half of a jumper cable and check the gauge.

[velojym]

Don't take this the wrong way; you are making this harder than it has to be. Just test voltage at the back of the alt and ground for 13.8 volts if you don't have it replace the alt. If you have 13.8 at there and not the battery then replace the wire from the alt to the starter with the fusible link installed inline.
No need to wait until you pull the engine. Also you don't need to pull the engine to make repairs to the wire harness. I removed my entire wire harness to make the changes I wanted and reinstalled it when I was done. Its easy to just unplug untie and unbolt and pull it out.  There is no better way to inspect it and know where you are really at than to lay it out on your workbench.
If you really want to run a wire from the alt to the battery to see if it charges the battery per your gauge. Just hook up one half of a jumper cable and check the gauge.

Oh, I'm not waiting to pull the engine, just figuring a way around needing a meter, as mine is having issues right now. The engine pull will happen sooner or later, as funds and time allow. The install was just too sloppy, and there are too many leaks. At the very least, I want to go over the mill and replace all the seals, clean everything up, paint the valve covers, and go over all the bay wiring. I'm just looking for a patch-up solution that'll get me by until then, without torching poor Earl.
I do have a habit, sometimes, of overly complicating things... possibly a result of having way too many years behind the wheel, letting my mind run away with stuff.

[jaredts]

You can't own an old truck without a multimeter.  Just go buy a $10 one.  With a little probing and tracing you can figure out what is going on and fix it right.  This will be easier to solve now before you pull the engine.

[1980c10]

Just hook up one half of a jumper cable one end to your pos on your battery and one end to the back of your alt and check the gauge to see if the voltage gauge in your truck moves up a little.
Doing this bypasses the fusible link and wire leading to your starter.
If the voltage increases replace the wire and fusible link.