Replaced My Gauge Cluster - Quick Question

[FahnSquatch]

Hi Everyone! I recently just replaced my gauge cluster on my 87 K20. What I did not realize is that the cluster I replaced mine with did not have a check engine light as it was from an earlier year. It instead has a choke light. Will the choke light act just as my check engine light for any codes the truck may show?

Additionally, I replaced all the bulbs in the new gauge cluster before installing it, however, nothing lights up behind the gauges. Just the choke, 4wd, blinkers, seat belt or whatever the 2 are under the fuel gauge. I can't remember what they were. Started snowing up here today so I will be waiting until tomorrow to check the fuse for the instrument lights.

 

[75gmck25]

I think it may be too complicated to try to use an earlier cluster in an '87 with a computer and TBI.

Your '87 may have some significant differences from an earlier cluster, since earlier models did not have a computer and had a mechanical speedometer without VSS. You need to do some research on what is different and see if you can work around the changes.

Bruce

 

[FahnSquatch]

I think it may be too complicated to try to use an earlier cluster in an '87 with a computer and TBI.

Your '87 may have some significant differences from an earlier cluster, since earlier models did not have a computer and had a mechanical speedometer without VSS. You need to do some research on what is different and see if you can work around the changes.

Bruce

Hi Bruce,

Thanks for the response. The 87 has a mechanical speedometer as well. I believe GM started incorporating the VSS in 88. The only thing I have found to be different between the clusters from the earlier years is the Choke light.

Thanks,
Fahn

 

[CrazyArk]

If it helps when I first got my 1986, I had to redo the lights on my own cluster, took fine grit sandpaper to the contacts on the bulb socket and the PCB, incidentally painted the guages too. It took that to get a good contact surface to provide power to the bulbs again, and they all work. Definitely make sure you get those contacts shiney again.

My 86 has the choke light as well, but the check engine spot had an independent light line branch going to two added spots above the speedometer and gas guage. And that was actually embedded into the dash bezel. Independent of the instrument cluster.

 

[AuroraGirl]

Youll need a functional check engine light to find codes.. so definitely important to have the right PCB for the cluster. Is your old cluster have a working PCB but just need new everything else around it? If so, use that on your new cluster and change the choke decal for a check engine, which should be sitting on little tabs and come right off and fit

 

[FahnSquatch]

Youll need a functional check engine light to find codes.. so definitely important to have the right PCB for the cluster. Is your old cluster have a working PCB but just need new everything else around it? If so, use that on your new cluster and change the choke decal for a check engine, which should be sitting on little tabs and come right off and fit

The reason i had replaced the cluster was because i did not have properly working gauges, ie: oil pressure, fuel level, and battery. On the old cluster the 4wd, seat belt, parking break lights worked. I cannot remember if the check engine light worked, I do not remember ever seeing it. I will have to check it out tomorrow. Maybe I will have to order a new PCB? The older one did look pretty rough.

 

[AuroraGirl]

You would be best off with a good quality cluster with a new PCB that has the right connections for the connector in your truck. If your truck is an 87 with a check engine light, TBI, etc, you will want an 87 PCB with those provisions. the check engine light should be on at key on engine off for a short bit much like brake and seatbelt should temporarily

 

[HotRodPC]

The reason i had replaced the cluster was because i did not have properly working gauges, ie: oil pressure, fuel level, and battery. On the old cluster the 4wd, seat belt, parking break lights worked. I cannot remember if the check engine light worked, I do not remember ever seeing it. I will have to check it out tomorrow. Maybe I will have to order a new PCB? The older one did look pretty rough.

The printed circuit may be diffferent. If you're just replacing due to faulty gauges, simply remove the gauges from the old cluster and install them into the current one. Printed circuit to match your current harness is paramount.

Did you do any diagnoses as to why your gauges aren't working right??? Don't take it personal, but you're likely to get an ass chewin' for NOT diagnosing a problem FIRST. That's what we're here for. What are the gauges doing exactly? I have a funny feeling your cluster is fine but you have some grounding issues. It's a common problem. These trucks are over 30 years old, they ground just to sheet metal. The screws and connections become corroded and cause the gauges to malfunction.

 

[HotRodPC]

I think it's actually 89 the speedo goes electronic.

 

[HotRodPC]

If it helps when I first got my 1986, I had to redo the lights on my own cluster, took fine grit sandpaper to the contacts on the bulb socket and the PCB, incidentally painted the guages too. It took that to get a good contact surface to provide power to the bulbs again, and they all work. Definitely make sure you get those contacts shiney again.

My 86 has the choke light as well, but the check engine spot had an independent light line branch going to two added spots above the speedometer and gas guage. And that was actually embedded into the dash bezel. Independent of the instrument cluster.

This, and the same for your gauge socket terminals. Clean them and plug the gauges back in. Make sure you're getting good solid connections to the cluster which has the printed circuit directly behind them. Also, the plastic turns a dull yellowish color. Guys will repaint it clean white. The clean white will make your dash lights brighter. Somewhere around here, we have a thread where a guy pretty much what he called rebuilding his cluster by taking it apart, cleaning all the terminals and contacts, replacing the bulbs as needed, painting the housing etc. It all worked great again when he was done. Maybe someone can search it and find that thread and bring it here.

 

[FahnSquatch]

The printed circuit may be diffferent. If you're just replacing due to faulty gauges, simply remove the gauges from the old cluster and install them into the current one. Printed circuit to match your current harness is paramount.

Did you do any diagnoses as to why your gauges aren't working right??? Don't take it personal, but you're likely to get an ass chewin' for NOT diagnosing a problem FIRST. That's what we're here for. What are the gauges doing exactly? I have a funny feeling your cluster is fine but you have some grounding issues. It's a common problem. These trucks are over 30 years old, they ground just to sheet metal. The screws and connections become corroded and cause the gauges to malfunction.

First and foremost, I will not take this personally lol. I am a newb to these squarebody chevy trucks and cars this old in general. I am hoping to learn some tough lessons and be able to make better judgement going forward. The reason I replaced the cluster was because I got this other cluster cheap cheap cheap. I will be taking the cluster apart and looking into what is going on. My oil pressure gauge would bounce around and never read properly. The batter gauge just sat at 8, and the fuel level gauge goes would tell me that i was beyond full when i was empty. My engine temp gauge has never worked just sits at the low end and doesn't move. Additionally most of the mounting tabs for my old cluster housing were broken. I guess i should probably take the two and turn them into 1 solid cluster.