dbryan23
Junior Member
- Joined
- Mar 14, 2023
- Posts
- 10
- Reaction score
- 13
- Location
- Georgia
- First Name
- Donald
- Truck Year
- 1978
- Truck Model
- K10
- Engine Size
- 400 SBC
Just wanted to post a quick thread in case this can help somebody in the future. This is for a 1978, but I guess might be applicable for 80s models also.
I had a problem with no instrument cluster lights. Headlights, marker lights, etc. all worked. So did the light for the fan/heater control panel. The fuse had power to it (although only like 8.8 volts instead of 12 for some reason).
I unplugged the wiring harness from the back of the instrument cluster just by reaching up under the dash... I didn't have to remove the cluster or anything. I used a multimeter to check power to each of the little metal contacts on the plug and found that 2 or 3 of them had power, but only one of which only had power with the headlight switch on. That was contact #2 on the plug. I was able to look up at the back of the cluster and, lo and behold, the little contact strip that should align with #2 on the plug was bent and sort of folded over. I straightened it out, stuck the plug back in and bingo... cluster lights are working.
So before you go through a whole lot of dismantling to try to fix instrument cluster lights, unplug it and check that A) #2 is getting power when the lights are on and B) the very thin and flimsy contact strip that integrates into the circuit system isn't twisted out of place.
I had a problem with no instrument cluster lights. Headlights, marker lights, etc. all worked. So did the light for the fan/heater control panel. The fuse had power to it (although only like 8.8 volts instead of 12 for some reason).
I unplugged the wiring harness from the back of the instrument cluster just by reaching up under the dash... I didn't have to remove the cluster or anything. I used a multimeter to check power to each of the little metal contacts on the plug and found that 2 or 3 of them had power, but only one of which only had power with the headlight switch on. That was contact #2 on the plug. I was able to look up at the back of the cluster and, lo and behold, the little contact strip that should align with #2 on the plug was bent and sort of folded over. I straightened it out, stuck the plug back in and bingo... cluster lights are working.
So before you go through a whole lot of dismantling to try to fix instrument cluster lights, unplug it and check that A) #2 is getting power when the lights are on and B) the very thin and flimsy contact strip that integrates into the circuit system isn't twisted out of place.
