Crazy Cluster - Need Ideas

[chubbusket]

Hey, been chasing an electrical issue for a few days now but can't seem to solve it. The problem is that my cluster readings are all way off and when you cycle the key / light switch they get even more wrong. When I say way off I mean that the gauges are usually buried one direction or the other. So, obviously the resistances on these circuits are wrong. I had the whole interior / harness out to clean up mouse issues and I checked and fixed any breaks in the harness. Everything is plugged in correctly as far as I can tell. I just did the big 3 and I know the dashboard, block, and frame are grounded very well. I also made a new ground for the firewall. The gauge grounds are connected properly and are grounded (also verified at cluster plug). Just to be sure I cleaned all of the cluster contacts with sandpaper and alcohol 3 times and it still doesn't work right. The issue did not appear to be the plug since tugging on the plug while the cluster was attached didn't have any effect. Any ideas of what else to check? Is there some other ground for the gauges I might be missing or some other wire I should check?

For reference it is a 97 K2500hd with a 5.7 / auto

 

[RichLo]

Are they off while running or just when you cycle the key and light switch before you start it?

 

[chubbusket]

I haven't tried it with the engine running since it is unable to be moved from the garage at the moment. But I did take some pictures of it.

This is with the ignition and lights off

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This is with just the lights on

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This is withjust the ignition on

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This is with lights and ignition on

To me it looks like an issue with the lights but they are all grounded properly. And the gear selector light doesn't show up when the lights are on...

 

[chubbusket]

Tonight I'm going to replace the power cable for the distribution box and see if it makes a difference. I was also considering reseating the harness connector through the firewall. Not sure what else to try at this point but I might just have to dig the dash apart again...

 

[RichLo]

Try starting the truck and see if the problem stays.

 

[351FUN]

You've got the ground under the dash hooked up too? That's how mine acted when my ground came off. Whenever something acts really weird it's almost always grounds.

 

[1500z71]

Agree with the grounding issue. I have an issue in my cluster where the speedo will jump up and slap 90 and then float back down to normal, and it only does it on cold starts and when I use cruise control. No idea where to start looking on that one.

 

[PEIslander]

I had a similar issue. My guages and lights would flicker and the truck would hesitate- only when driving. Found both ground straps rotted off. Replaced and it's all good

 

[chubbusket]

Thanks for the ideas but I still don't know what is happening. I agree it seems like a ground issue but I don't know how it could be. I just did the big 3 and ran 0 awg grounds to the body and made a new firewall ground. I ran a wire from the battery ground for testing directly to the cluster ground and it still acts up. I started the truck and it still doesn't work right while running. Also, I checked continuity on the cluster grounds from a wire directly to the battery ground and it all is connected. Based on the testing I have done I think the issue might be a short in the parking lights or an issue with the hazard flasher. Everything seems to work fine until I turn on the lights. I did just install a remote start on it but all components in the truck work fine, just not the cluster. I also ran a new power wire to the accessory box and retightened the firewall connector. Haven't blown any fuses... really not sure what else to check.

 

[chubbusket]

Just to finish off this thread in case anyone finds it later... I found the issue and it was because of a bad ground. But the ground was bad where it connected near the glove box before it goes through the firewall and attaches to the block. In another thread I explained that my truck had some mouse issues that I cleaned out in another thread called **** Mice. Well, the inside of this connector had so much mouse bodily fluids in it that the connector didn't seat fully. I cleaned it out better for the third time and then all the gauges just started working. I did a lot of diagnosing before that and found that the parking lights were grounding through the cluster and causing the problems. So, the moral of the story is to keep mice out of your truck. I finally got the whole interior back together and passed my state safety inspection so I'm happy now.

No,that connector isn't burnt it's just some leftover mouse doo doo.

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