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I've finished the interior rebuild / reinstall of all the trim, carpet, seats, door panels, dash and dash pads... now I'm installing the upper center and center consoles and I've run into an issue; the dash lights are not coming on when I pull the light switch. The headlights come on, but no dash lights. I didn't have my circuit tester with me today but tomorrow, the first thing I will check is the fuses to ensure I've got power. Assuming I've got power, besides the light switch itself, what else could be causing this?
Did you make sure the light switch pull **** is turned all the way counterclockwise to just before the "always on" detent?
As I recall, the bulb housings need to be in contact with a ground which doesn't happen until they're snapped into the gauge panel. You can test the bulb sockets by touching the bare metal at the bulb end with an aux. ground wire.
Yep, I've made sure the pull handle is pulled all the way out and completely counter clockwise before the detent. I'm concerned because it appears the dash lights (speedo, Tac) are not on - but I'll continue you check - thanks!
OK, today I checked my Fusebox for power and I found that all my fuses are fine EXCEPT there is no power going to "Inst" fuse, regardless of key position so I think this is my problem - thoughts? Has anyone else had a Fusebox fail? I've never heard of this... 71 Corvette Fusebox
Hmmmm…short of pulling the harness plug engine bay side I don’t know. I know there can be corrosion in there. Before installing my new engine and headlight harness I plan to No-Ox-Id every one of those contacts. Have you tried maybe a little pressure or wiggle there at the “inst” supply side fuse clamps/tabs? If you do so, and get a little blip of those lights, then a loose or corroded connection is evident.
”Problem Solver Garage” has a C3 series of vids on youtube where he goes through his harness, as well as degunking his harness to fuse box connections. Just don’t do what he does with the dielectric grease though. I think that could cause a whole new set of issues.
He has 3 vids on the harness. In this one, he cleans those contacts. Maybe a bit rough around the edges, but he does get the job done.
Missing ground wire is the most likely cause. But there might be a problem with the light switch, preventing power from getting to the bulb. You will need to probe ONE of the dash bulb sockets with your VOM while connecting negative proble to KNOWN good grounding point (NOT dash metal).
I actually found a post from 10 years ago from a guy that had the same problem as I do. I will come back tomorrow with my results... The power does not go to this fuse until the headlight switch is pulled (power from the tail light fuse). Tomorrow, I'll pull the headlight switch, THEN check for current. If I'm lucky, I just have a blown 5-amp fuse. Wish me luck!!!
I actually found a post from 10 years ago from a guy that had the same problem as I do. I will come back tomorrow with my results... The power does not go to this fuse until the headlight switch is pulled (power from the tail light fuse). Tomorrow, I'll pull the headlight switch, THEN check for current. If I'm lucky, I just have a blown 5-amp fuse. Wish me luck!!!
OK, sorry but it seems my posts from yesterday were cut short. After working with a friend and the wiring diagram, I found the instrument lights get their power from the headlight switch and sends the current through (Dark Green wire) to the instrument lights and the fuse is just in the circuit for protection. To verify this we used a circuit tester and determined current coming to the light switch with several wires but when we pulled the headlight switch handle out, no power was going to the Dark Green wire (no instrument lights). We disconnected the plug and applied power directly to the Dark Green wire and the instrument lights came on. Today, I ordered a new light switch. This should solve the issue...if it doesn't I will reply.
Just to close my thread out, I replaced the Headlight switch today and that restored the instrument panel lighting. Thank you to everyone for your wisdom and input!
Just to close my thread out, I replaced the Headlight switch today and that restored the instrument panel lighting. Thank you to everyone for your wisdom and input!
C3 72 - Dashlights not working
