Body ground location needed

1985 CHEVROLET S-10

322,000 MILES • 2.8L • 6 CYL • 2WD • MANUAL

BLAZ85

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I have the vehicle listed above Blazer semi-restored that I have owned for almost 30 years. It seems to me that the instrument panel lights are not as bright as they once were. I have replaced the bulbs and cleaned the contacts but that did not help much. My thought is maybe they have a poor ground.
My question is, where is the body ground for the instrument panel light circuit located?

Thank you in advance for your reply!!

Jan 21, 2021 at 7:32 PM

KASEKENNY

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Unfortunately, the wiring diagrams were not the greatest back then but I attached the info below. It appears that the C5 location is the ground for this but we can test this to find out if the ground is the issue. Here are some guides that will get us started:

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Let's access the bulbs and do one of two things. First use a meter to test resistance from the bulb ground to the frame. You don't need to test directly to the actual ground location as all the grounds are connected to the frame either directly or indirectly so if you have a good connection then you will have low resistance.

The other way we can test this is to just run a redundant ground with a jumper wire and see if the light is brighter. Also, we should check voltage at the bulb as it is possible that we have a battery ground issue.

Basically these bulbs need full 12 volts and a good ground to be as bright as possible so we need to check both. Let us know what you find. Thanks

Images (Click to enlarge)

Jan 23, 2021 at 5:58 AM