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LS swap dash problem

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skyhigh4by

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I swapped in a 91 cluster for my LS swap. I just repinned the plug but now the only thing that seems to be working is the instrument lights. I have no gauges or warning lights (seatbelt,brake,4x4,ect...)also the buzzer isn't working anymore either. Am I missing something. The 2 red wires from underhood through the firewall junction to fuse panel/ignition switch have power..
It's like I'm missing a ground or something
 
What year is your truck? 91 as well?

The 90/91 trucks have very different pin out connections than the earlier 78-89 stuff and actually have a different plug as well.
 
It's a 91 cluster in to an 82 cab. I followed a pinout diagram I found and swapped all the wires around to the new plug. I did end up with a few wires unused though. I think 1 or 2 ground wires maybe and also the wires that did run the volt gauge before. There was no spot for those wires in the new cluster plug...
 
skyhigh4by said:
It's a 91 cluster in to an 82 cab. I followed a pinout diagram I found and swapped all the wires around to the new plug. I did end up with a few wires unused though. I think 1 or 2 ground wires maybe and also the wires that did run the volt gauge before. There was no spot for those wires in the new cluster plug...
Click to expand...

The cluster is really simple, all the traces are labeled. The newer cluster was "wired" a lot easier than earlier, did not use as many ground and power feeds, thus less wires at the plug.

Factory wiring diagrams are in my signature, use those for pinout, however there is enough variation it's likely just easier to figure out which wire is which gauge sender, and ensure they match up to the cluster pinout properly. You can write on the cluster flex circuit with a sharpie, the cluster connector is numbered or lettered for each pin, so you can use that info to make sure you get it right.
 
dyeager535 said:
The cluster is really simple, all the traces are labeled. The newer cluster was "wired" a lot easier than earlier, did not use as many ground and power feeds, thus less wires at the plug.

Factory wiring diagrams are in my signature, use those for pinout, however there is enough variation it's likely just easier to figure out which wire is which gauge sender, and ensure they match up to the cluster pinout properly. You can write on the cluster flex circuit with a sharpie, the cluster connector is numbered or lettered for each pin, so you can use that info to make sure you get it right.
Click to expand...
I was pretty sure I had it all right but I guess I'm gonna have to go over again to be sure. It just seems like a power or ground supply is missing because nothing at all but the background lighting works. What about the brown wire that used to come from the alternator? Could that have anything to do with it at all?
 
Alternator wire is used to excite the alternator and get it charging. Is that the brown one you are talking about? Shouldn't have been one prior to 1990(?) since the alternators didn't use the same setup.

I'm making an educated guess here, since the cluster lights work your ground is probably good, but your power is a likely issue. The cluster lighting power comes from the light switch so that it can be dimmed.

Edit: And for some more clarity...all the gauges share the +/-, the sending unit wire is the only difference, excepting the voltmeter, which only has the +/- on it. If it doesn't work, pretty obvious the problem is with the power or ground.
 
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Ok. Yes I was talking about the alternator exciter. It's dead ended at the firewall because alt now plugs in to my new LS harness. I'm thinking power issue too. Both heavier red wires from underhood w/fuseable links from starter&alt)through firewall have constant battery power though. im missing a power source to the fuse panel somewhere I think? Headlights and everything seem to be working. Just dash and ignition buzzer
 
Are you using the '82 fuse panel still? I can't recall the layout off the top of my head, but there is an inst/cluster fuse no? Check for 12V there if you suspect it's a power issue to the panel.
 
Found gauge fuse blown. Replaced and it popped again as soon as I turned the ignition on. What all is in that circuit that could be shorting out?
 
Agree with Russell. Easiest is going to be to pop the cluster out, and just check each pin on the connector for short to ground. Can't imagine how the cluster could be messed up like that.

Simple test would be to disconnect the cluster, then check for short to ground on the instrument panel fuse. If it still exists, you know it's in that wiring, not the cluster.
 
So it turns out I'm an idiot. Doing the cluster swap resulted in a few old wires not being re-used. A couple grounds and another one that was the + for the voltmeter. Somehow in all of my wisdom I left the pins on the ends and wrapped them all up together. The 12v supply was shorting out on one of the ground wires.

The next problem Im having is now the 4x4 indicator is on full time. It used to have its own separate bulb holder/wiring but the 90 cluster its built in. I put the pink w/black stripe wire in to pin #12 on the new cluster. The truck isn't mobile yet because Im still waiting for my ECU back from tuner. Possibly is it just the switch in the t-case not disengaging until I'm able to roll the truck around a bit?
 
skyhigh4by said:
So it turns out I'm an idiot. Doing the cluster swap resulted in a few old wires not being re-used. A couple grounds and another one that was the + for the voltmeter. Somehow in all of my wisdom I left the pins on the ends and wrapped them all up together. The 12v supply was shorting out on one of the ground wires.

The next problem Im having is now the 4x4 indicator is on full time. It used to have its own separate bulb holder/wiring but the 90 cluster its built in. I put the pink w/black stripe wire in to pin #12 on the new cluster. The truck isn't mobile yet because Im still waiting for my ECU back from tuner. Possibly is it just the switch in the t-case not disengaging until I'm able to roll the truck around a bit?
Click to expand...

At least on a 205, the switch is tied into the shift rails, so no, it probably doesn't have anything to do with being mobile. If it's 2WD and the light is on, something else is likely the issue. I'm guessing the earlier wiring is setup opposite the 90-91 due to the change in cluster circuit layout.
 
I'm thinking the wiring is opposite as well. The cluster light needs a power source to illuminate but I'm pretty sure the switch is a ground source. Is there some way I could remedy this problem? Maybe use the old bulb holder/wiring in the new cluster and leave the cluster harness empty in that pin?
 
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