Hi me again. Dashboard lights. I have everything apart except tach and speedo still attached to dashboard. I found the two wires that connected and blew the instrument light fuse. Fixed them. Still no lights. Found 2 wires that were connected to ground Seem like owner installed. Not connected to anything else. I touched the metal of the Center Gauge & Clock Surround Bezel and the lights came on on the center but not the tach and speedo. Seems to be a grounding problem in the harness. I think I have 3 choices. Spend a lot of time and money and put a new harness in (last choice), connect the ground wire to the center cluster and find out where to connect the other ground to the Tach and Speedo lights. The 2 wires are the yellow and the orange with black stripe. I was looking for a loose black wire from the harness to ground then any wire color loose. Nothing. Any suggestions?

 

The ground for your dash lights comes from a ground wire that attaches to the left side of the bird cage frame. The bulbs only have a single grey wire and the metal frame of the gauges assembly is then grounded to complete the circuit. there should be a stab-on connector on your panels for the ground wires to fasten to. Look at the red circles on the picture of the gauges.

 

 

Great help here. I connected new grounds to both of them but still no lights. Seems to me that all the instrument lights come through the same power harness are fed by the headlight rheostat switch. What could be causing the center cluster lights to work when I fix the ground but not the speedo and tach lights? Hi beam light, turn signals work, headlights work high and low beam. I am lost again. HELP

 

all the bulbs use the same source for 12 volts and that comes from the headlight switch. Don't know the year of your car, but in 69 there was a green wire from the headlight switch to the instrument/lamps 5A fuse in the fuse block. From there is goes out as a grey wire to the bulbs. Somewhere before the center console and the gauges it has to branch out into separate wires and bulbs. Don't know exactly where that breakout is. It might be somewhere in the harness. See if you can find the wires to the console and then find the wires to the dash and there must be a connection somewhere between them. Have you checked for 12volts from one of the sockets to the frame of the car to ensure you have a good ground. Check one of the working sockets in the console also to double check your ground.

 

Well we have a solution. It seems the previous owner installed an aftermarket made for Corvette radio. It didn't work well so I bought a better one. Worked great. We kept chasing dashboard lights and finally discovered a 35 amp draw on the interior light circuit.. Traced it back to the radio. Seems the previous owner thought for the radio lights to work they needed to be connected to the interior lights circuit. Dumb me connected the new radio to the old radio power connection. We disconnected that and connected the radio correctly. No more interior light fuses blown and interior lights work fine.

Now I don't have low beam only high beam and one light bulb is burned on high beam. New dimmer switch and I checked its functionality. It switches from circuit to circuit. Guess I will have to dig more to find out if the previous owner did another wonderful ad lib wiring modification unless you guys can provide assistance.

I did change out the posistive wir connection from battery to generator with battery terminals connected. I know dummy me. Got a ground strike and some smoke from the passenger side firewall area. Everything seems to work fine except 1 buld and no low beam. Is my dumb move not disconnecting battery connected to my no low beam burned out light problem?

Thanks again in advance. At age 76 it is becoming more difficult to get body and hands in positions to do things like headlights. My hands ar finally healing from all the scrapes and cuts associtaed with taking apart and puttin together the entire dasshboard assembly. I am a little reluctant to just start ripping into the headlights without a possible solution. Did a quick check of the bulb circuit with a Voltmeter to see it was powered and it is so I assume the bulb is burned. Can't muster enought finger strength to release the spring to change the bulb so I want to be pretty positive that is the issue.
Your advice is always appreciated.