73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Topic started by: Skunksmash on November 06, 2011, 06:51:40 pm
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This thread is for those of you who are familiar with the gauge cluster innards. 87 model. I'm not happy with the way I currently have my gauges set up. I don't have them mounted like I want them. Well, I think I can get them all recessed behind the factory bezel, using the factory printed circuit if I do this right. The printed circuit will bend, unlike other setups where they use one of those green PCB boards. That is the only reason this method will work. I think...
Anyway, I plan to take the appropriate grit of sand paper, and sand off a couple of very small spots on the printed circuit, to expose the copper filament underneath. Just enough to make a place to solder. Then solder the wire that I'm needing to run, to that copper thing. Then throw down some clear silicon or something on the solder point to sort of strengthen the solder point. If the sanding part is even necessary. It might not be necessary if I can just solder to the already exposed copper points on the printed circuit, that were originally open so that they could contact the lights and various power points and signal emitters and stuff.
To make a hole in the factory gauge housing, I'm going to just cut a hole in it large enough to fit the new 5" tach. I've checked and there appears to be room. I will lose the "fasten seat belt" and "Parking Brake" lights that come factory in the dash, but I don't really care. So since the printed circuit can bend, I can just bend it and fasten it over somehow. That way my big tach can fit where it needs to go, and so I don't have to ditch the stock setup for the rest of the gauges. Can't really afford to buy all new gauges right now but I did get a few of the necessary ones. Necessary at least, in my opinion. So what do you think? Can you forsee any problems with this idea?
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Not having a fuel gauge...
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Why not just get a factory gauge cluster with a tach and not have to cut the circits at all?
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Factory tach looks kinda...abnormal with zeros after the numbers. Looks like some kind of other speedometer or something. But I wasn't going to cut the circuit, I was going to fold it over a little and leave it that way. Also, the fuel gauge will be replaced with a smaller one that I have, which will be fitted into the clock's old spot.
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Maybe I'm misunderstanding, but a new aftermarket tach will require a bat. pos., lighted pos. from dimmer (for backlight), ground, and tach signal wire. None of those would I get from the printed circuit, so I don't see the need to sand and solder to the pcb. You just have to run a few wires and figure out how to physically fit it in there.
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Ditto on what jaredts posted. Of course I am still confused as to what you want to do...
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Sorry I should have been more clear on that. Yeah the tach will have to have its own wiring of course, but the new autometer fuel gauge and the digital water temp gauge might be able to benefit from just having their wiring (some of their wiring at least) soldered to the correct spots on the factory PCB. That way, I don't have to deal with the dimmer aspect of things, which I was never able to get working on any more my gauges. Didn't try real hard though. Also, if I am stuffing this tach in there, the PCB does have to be folded over simply because there is no longer room for it with that big tach in there. So that presents a couple of minor issues. I'll post up a couple of pics tomorrow.
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Ok here are some pics that might help explain what I want to do. I'd like yall to look at them and tell me what you think. Good, bad, or ugly. And maybe some recommendations.
(http://i459.photobucket.com/albums/qq318/justinsn95/Cluster2.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Cluster1.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Cluster3.jpg)
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Are you planning on keeping all the other stock gauges? I started down this path and you will end up hacking that cluster housing to death.
Honestly you would be better off going this route:
http://73-87.com/7387garage/interior/gauges_recessed.htm
(http://73-87.com/7387garage/interior/gauges_mike/Jeffs/gauge%20view%20front.JPG)
(http://73-87.com/7387garage/interior/gauges_mike/Jeffs/gauge%20view%20rear.JPG)
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Yeah I'd like to do that, but only working part time due to school I simply can't afford to buy everything necessary. I can only do a little here, a little there. And for now, yes I do plan on keeping the other stock gauges.
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Why would you have to fold the printed circuit over? Couldn't the tach just bulge out the back and push it back a little?
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I guess you could, but it does still need to be secured some kinda way. Cause I don't want it just being loose back there.
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If you are worried about the printed circuit, just tape it down, just don't crease it.
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Ok now I have to drag this topic back up. Is there some kind of tach lead wire on the coil of an 87? I am about to wire up my tach properly, and it looks like there is some little wire coming off the coil. Just a little 4 inch wire with a little plug on the end of it, coming right out of one side of the plug that plugs into the coil. I thought this could be awful convenient for me, if its just a negative test lead that goes straight to the coil. I could just wire my tach signal wire, right to the little plug looking thing on the end of the wire. Its not plugged into anything, so I have no idea what its for.
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The HEI has a plug for TACH, just use that.
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Ok if I am understanding, an HEI is when the coil is mounted on top of the distributor cap? My coil is off to the side. Just wanted to put that out there in case its relevant to this situation. Dang 87 being different from all the rest of the trucks around here lol
Don't know much about HEI, just read up on it here:
http://en.wikipedia.org/wiki/H.E.I.
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forgot that yours is TBI. There should be instructions on how to hook it up that came with the Tach.
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Now I need to ask about my fuel gauge. I bought this:
http://www.amazon.com/Auto-Meter-3514-Short-Electric/dp/B000CIJ5YC
Because it reads in the range of 0-90 Ohms of resistance. 0 being empty, 90 being full. (I think...) According to autometer the range for mid 60's to mid 90's GM vehicles is 0-90 Ohms of resistance. As my truck is an 87, it seemed that the 3514 sport comp fuel gauge is what I needed since it meets those requirements. However, for some reason, the needle just stays pegged out a way beyond a full tank of gas. I simply soldered the wire to the corresponding copper contact point for the fuel sender on the printed circuit. It seemed to work just fine for my digital water temp gauge.
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Did you recheck your soldering job to make sure you did not damage something. Sounded like it should work just fine.
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Yeah I'll need to recheck.
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I'd also like to see a diagram of the interior fuse box if anyone has one. I'm looking for an empty accessories slot that comes on when you turn the key on. If there is one.
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On an 87 it will be labelled ING
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Thanks a lot man that helps. I accidentally wired up my water temp gauge to only come on when the headlights come on lol. Not very useful. But I do find it odd that they would have an orange wire that they say to wire to your +12v headlight switch, and a red wire that they tell you to wire to your +12v key on power source. Wouldn't you just need the one for the key on power source?
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Orange is for the light inside"night time driving"
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So theres two separate lights in there. One for the LED temp display, and another that is just some kind of backlight.
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Gages typically have a separate power wire for the backlight. This is so it only comes on when your dash lights are on (parking lights/headlights on), and also so it dims along with your dash lights when you use the dimmer. It should work fine if you connected it to the accessory power or twisted it onto the accessory power of the gage, but you wouldn't have the functionality I mentioned.
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Ok well thanks again for all the help everyone. But is this the negative side of my coil? I think it is but I have to be sure cause Autometer says you'll ruin the gauge if you hook it up backwards.
(http://i459.photobucket.com/albums/qq318/justinsn95/coilneg.jpg)
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I would just check but I got to get a new voltmeter.
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That is the wire for your tach.
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Yeah I always wondered what it was. It seemed odd that it was even there, given that the truck did not come with a factory tach.
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So now I'm down to the fuel. I got the tach and the new water temp gauge going good, but this new fuel gauge is giving me some trouble. My truck has two tanks, and that is making it difficult for me to just trace the correct wire all the way to the dash.
I need to locate the exact point I should solder to on the printed circuit. There are only 3 options, as I'm sure many of you are aware. The factory fuel gauge had only 3 plugs (or prongs) sticking out of the back. These 3 prongs just plug right into the little metal things that attach directly to the printed circuit itself. So I started out by just soldering the autometer contact points to the printed circuit. These trucks use 0 Ohms for an empty tank, and 90 Ohms for a full tank. For some reason the gauge must be reading far beyond that, cause the needle on it immediately dove down to way past the "Full" mark on the gauge. And stays there even once the whole thing is installed back into the truck.
So am I doing something wrong here? Is there some reason that soldering this won't work? Maybe I am creating too much resistance by soldering? I don't want to just keep guessing and soldering and then desoldering, cause I don't want to ruin my precious printed circuit. I need to get this right the first time. Well, the second time I mean. I can't just keep trying things.
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I would have suggested first running test leads to the gauge from the traces you intended to use to make sure the gauge functioned properly. I would say you probably have the wires backward, as a good solder joint will have negligible resistance, and you are simply applying voltage and ground to the wrong poles of the gauge.
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That is a good idea. See I knew I just needed some new clear head to help me think about this.
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Ok here is where I am now. Finally got more time to work on this project. It just sits there for months at a time sometimes lol. Anyway, I got everything all figured out with the gauges except one last detail. I took some pics to show you what I'm talking about. If you look at the pic of the factory plug, that plugs into the gauge cluster itself, you can see that each little "pin" is numbered on each side. With use of a Chilton's manual, I have narrowed the sending unit wire down to either the number 18 pin, or the number 16 pin. Gotta be one of those two. One the page it says that its pink. Yet both are pink, but one has a stripe.
I highlighted on there to make it easier to find.
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge9.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge8.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge7.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge6.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge5.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge4.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge3.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge2.jpg)
(http://i459.photobucket.com/albums/qq318/justinsn95/Gauge1.jpg)
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If you have dual tanks, the wiring is routed to the tank switch. the one coming straight out of the harness runs to the back and terminates. The one from the switch plugs into the one on the harness and runs down to the switch connector and then to each tank. Both of these wires go to the cluster, they are the tan/white on the bulkhead connector. Somehow the switch to pink in the #18 slot. If you are tying into the Pink #18, it should work.
Did your fuel gauge work before?
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Yeah it worked before, although poorly in my opinion. The new one doesn't seem to have that wavy needle problem that got on my nerves. Guess I'm just a perfectionist or something. But I did get the new fuel gauge going finally. It is the number 18 slot. All you really have to do is trace that slot on the printed circuit, to find your solder point. It turns out its the far left hole. The other two are just positive and ground. Thanks for all the help.
Now I just gotta get the tach going and I'll be ready to put the truck back together. As you can see from wiring diagram pic, the wire for the tach is white. Unfortunately, there are two white wires on the coil. One on the left, and one on the right. This is probly a dumb question but, shouldn't I just be able to use my Digital multimeter to figure out which side is negative and which is positive? Only get once chance at this one. Get it wrong and ruin the tach.
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Well now the dang tach has started giving me trouble. So to troubleshoot, can I just pop the hood, hook up the negative on the tach to the negative on the battery, the positive on the tach to the positive on the battery, and the signal wire to the negative on the coil? I'd like to test with the simplest configuration possible, so I can then rule out what is wrong. I'd like to just do it all right there under the hood. Is there any reason I shouldn't do this?
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Did I read this right? You are soldering your connections to the printed circuit? You should be going directly from the harness to your new gauge not the printed circuit.
http://forum.73-87chevytrucks.com/smforum/index.php/topic,9072.0.html
(http://i6.photobucket.com/albums/y228/Sabaka454/control.gif)
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Yeah. I am soldering directly to the printed circuit. I guess I didn't do it exactly right, but it was quick, easy, and it worked. And I gotta stop trusting the guy doing my soldering lol. He had the positive and negative reversed on the tach. Same thing he did on the fuel gauge to begin with. I suck at soldering, and he's very good at it. Just not so good at hooking up the connections to the right points heh.
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Yeah. I am soldering directly to the printed circuit. I guess I didn't do it exactly right, but it was quick, easy, and it worked. And I gotta stop trusting the guy doing my soldering lol. He had the positive and negative reversed on the tach. Same thing he did on the fuel gauge to begin with. I suck at soldering, and he's very good at it. Just not so good at hooking up the connections to the right points heh.
Maybe you could supervise more and look over his shoulder and just make sure he does it right, then you can the best of both worlds.
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Why would you solder your connections to the printed circuit instead of going directly to the wiring harness?
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Well the way I look at it, why not? Its all right there and I don't have to run all this wire and make all these connections when all you have to do is pull the gauge housing, and go to town soldering. Then simply plug it back up and it all works. Well, if you don't have your pos and neg reversed of course. I didn't have to cut into loom on the harness, or otherwise come up with some way to splice into those wires. I wanted to leave the harness alone if I could, and just plug it in and have it work.
I think I had this idea that I wanted to just alter the factory gauge cluster to be what I wanted it to be.
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On an 87 it will be labelled ING
Ok I used up the ING on the fuse box that already had a fuse in it. I just got one of those adapters with a wire on it that lets you plug in two fuses. You get 2 fuse slots in the adapter. 1 for the original fuse that was already in the ING fuse slot, and one for the new fuse that you want to add.
So now I need to make use of that extra ING slot. But how can I do it? There is a piece of plastic made into the middle of the slot, that won't let you plug in a fuse. Its like there are two smaller holes for the extra ING slot. What goes in there?
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Would it be easier to just tap into the circuit that you already added using the fuse adapter? I think a spade connector goes into the slot you are talking about.
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How would you go about that?
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I don't know what the added fuse and circuit was for or what you need another circuit for now--I guess I could go back through the pages of the post. If the fuse that you already added would be appropriate to also protect whatever you're doing now then I just meant to solder or use a butt connector of some type to tap into the wire coming out of that fuse. You could also buy an inline fuse and appropriate connector to plug into an ign slot in the fuse box.
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Yeah i got some spade connectors to try to use the extra aux ING slot. Odd that they made it to where a simple fuse wouldn't fit. I'm using the other ING slot for my new water temp gauge, and something else that was in there already, that I didn't bother to look up yet.
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They fit, got it all rigged up. Job done. So nice that they put some aux "key on" slots in there.
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Odd that they made it to where a simple fuse wouldn't fit.
I don't follow?and don't you mean IGN?
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A regular fuse won't fit in the aux IGN slots that they made available. And yeah i mean IGN i was used to this little honda i used to have where it was aux .
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Ok I got a problem. Do you guys know what signals to look for, on the Voltage gauge, and the Oil pressure gauge? I take it the oil pressure gauge is looking for a certain amount of OHMs of resistance, right?
And what is the voltage gauge looking for? Whats the signal?