Instrument Cluster Issues - SOLVED

[Capsalot1]

My instrument cluster is having intermittent problems, I found out someone has monkeyed with the security system so it might be related. Sometimes when you shut it off the security light is on solid. Everything starts working fine and then the problem pops back up again.

 

[rockola1971]

You are going to have to get a Tech II or equivalent hooked up and see if that light is a force on because of the security system OR just a internal problem on the Cluster Circuit board. It is not uncommon at all on these clusters to get silver migration which can bridge paths on the cluster circuit board which will cause all kinds of weird, chaotic, false indications, erratic or no needle movement and god only knows what else. Ive seen and heard it all on these clusters. Pull it out and clean the firewall connector, connector on circuit board and clean the circuit board itself with rubbing alcohol. The silver migration is essentially a corrosion that appears as whitish, grayish and even blackish crud on the circuit board. It can be fully, partially or not conductive at all. Its like adding in random resistor values to random spots on a circuit board and bridging random circuits together that are not even related to on another within the grand scheme of the whole electrical circuit. Give it a good cleaning then let air dry for 30mins or so. Use a soft nylon brush and even a scotchbrite pad lightly across areas with no components and only trace paths. Essentially a light buffing.

Im going to have to one day do a youtube video. This topic comes up alot on here.

 

[Capsalot1]

You are going to have to get a Tech II or equivalent hooked up and see if that light is a force on because of the security system OR just a internal problem on the Cluster Circuit board. It is not uncommon at all on these clusters to get silver migration which can bridge paths on the cluster circuit board which will cause all kinds of weird, chaotic, false indications, erratic or no needle movement and god only knows what else. Ive seen and heard it all on these clusters. Pull it out and clean the firewall connector, connector on circuit board and clean the circuit board itself with rubbing alcohol. The silver migration is essentially a corrosion that appears as whitish, grayish and even blackish crud on the circuit board. It can be fully, partially or not conductive at all. Its like adding in random resistor values to random spots on a circuit board and bridging random circuits together that are not even related to on another within the grand scheme of the whole electrical circuit. Give it a good cleaning then let air dry for 30mins or so. Use a soft nylon brush and even a scotchbrite pad lightly across areas with no components and only trace paths. Essentially a light buffing.

Im going to have to one day do a youtube video. This topic comes up alot on here.

I’ve done all that, no migration found, very clean. Cleaned anyway and touched up all solder joints to ensure there was no cold solder. I’ve verified 100% it’s due to the aftermarket security modification. I’m at a loss as to how to fix it because I can’t figure out what was done. If you don’t hold the cruise resume button and let the horn sounds it resets the gauges. If you turn the system off with the switch the gauges start glitching again.

 

[rockola1971]

Then some bonehead has spliced into the power to IC for the security system and you will have to track that splice down and correct it. What makes you think there is a security system add on? Is there a module? Have the model of the security system so I can pull up its schematics?

 

[Capsalot1]

Then some bonehead has spliced into the power to IC for the security system and you will have to track that splice down and correct it. What makes you think there is a security system add on? Is there a module? Have the model of the security system so I can pull up its schematics?

I apologize for disappearing, Ive been super busy, found someone had installed a bank of three relays that interrupted the yellow wire. Removed the relays and now its a hard fail and I can’t reset the gauges by holding the cruise button and letting the horn blow. Still not sure ir its the cluster or something outside triggers the failure. Im lost.

 

[Capsalot1]

 

[exp500]

See the cut purple wire? Check Wireing diagrams for it. Think that is part of Anti-theft.

 

[Capsalot1]

See the cut purple wire? Check Wireing diagrams for it. Think that is part of Anti-theft.

Where do I find the wiring diagrams?

 

[swathdiver]

Where do I find the wiring diagrams?

You can buy the pdf or disc from ebay sellers like SeriousCTBuyer and or pay for an online subscription to the shop manual at AllDataDIY.

 

[exp500]

You could look here too-

Helpful Links

Helpful links- If this is a successful post maybe it could be stickied! Here's the first- https://www.gmt400.com/threads/88-95-service-manuals.43575/ https://67-72chevytrucks.com/vboard/showthread.php?t=700011

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