I have Instrument Cluster and Light switch dimmer issues and I got this info from Google Can someone point me to the ground location A-pillar, under dash or behind instrument cluster

The ground for the instrument cluster and various dash accessories is located behind the dashboard on the driver's side A-pillar area. Specific Location: The ground point is typically found hidden behind the lower driver's side A-pillar trim/dash structure, often near the base of the pillar where the dash frame meets the body. Purpose: This ground is crucial for the instrument cluster, gauges, and potentially the steering column wiring.

 

G200 should be screwed to the metal "frame" of the dash housing on the LEFT-hand side of the steering column. G200 is a ground for many of the interior electronics. I don't have a pic handy,.. but it's pretty easy to find & accessed once the hush panels are removed. ( 1987 Service manual says "Behind IP, on LH side of Steering Column bracket )

S205 is a factory SPLICE that is wrapped-up inside the Dash harness; You can't just look for it & "find" it,.. In order to access/touch the factory S205 ground wire splice you would need too strip the harness of it's Loom and electrical tape (in just the right spot ! ).

Here is the factory Schematic for an 84-89 ( or so ! ) Camaro G200 circuit.

 

^^^ This ^^^

Popping the steering column out (about a 5-minute job for me, probably less than half that for you, because I'm slow as s***) makes it even eeeeeeeezzzzzyer.

 

Well said 😜

 

Thank you for the information. I found the Ground location. The Ground is good. Been chasing this instrument panel issue. The whole right side goes crazy when I have the Light switch dimmer all the way up. I spent 2 days troubleshooting this issue 😪

 

As for quick advise,..... Take a close look at the Light Switch; internal adjustment rheostat can cause problems on the 'power' side of the circuit.

Also check the INST"strument" circuit itself,..... The Cluster ( failing printed circuit ) is a common cause of the adjustable DIMMER ( backlighting ) circuit problems.


Here's a couple diagrams that might help; I don't think they are 87 specifically - but they should be as close as possible if you've got TPI.

 

John thank you for this information along with the wire diagrams. I suspected the light switch so I replaced it with a new one but still have the issue. I will next check the INST strument circuit and Light bulbs.