Help! Interior lights on my 75 update.

[lheindrich]

So I posted a thread the other day about my interior lights not working and I have not recieved any response yet so I decided to look a little further into things myself. I also checked old posts but have'nt found much help there. So first all my fuses are good, second I tested for voltage at the headlight switch and I have voltage at the orange lead and the red lead there are two brown leads a light blue lead a green lead and a white lead at the headlight switch. I checked other forums and they said voltage should leave the headlight switch on the green wire and run to the fuse box through the fuse then back out on the gray wires to the dash lights. So before I buy a new headlight switch I want to make sure that is the problem so I made sure I had good grounds first then I made a jumper from the orange lead with voltage to the green lead and still no interior lights. My question is have I done the proper trouble shooting to this point and if I have what could be wrong? Could someone out there in Corvette land help me because I am still in the learning process here and I do'nt know what to do next. Thanks for any input.

 

[TimAT]

DO you have the correct wiring diagram for your Vette? That's the single most help you can get.

A link:
http://www.nrjvette.com/johdotukset/Chevy Corvette 1975.pdf

I print these out as big as I can, then align the wires from page to page, tape them together and use a highlighter to trace an individual wire/circuit. Makes things easier..

 

[GTR1999]

I have the same problem with our 75. It was there when my son bought the car in July and we haven't gotten to it yet. Now I know a lot of the aftermarket HL switches are imported and not too good. I do have a good used GM switch here as well. Looking at a diagram for a 69 I have here it's probably the same as the 75's. The same color coding as you state. The green feeds the ins panel fuse, through the fuse to the gray wires which do feed the dash lights,gauges, radio, heater control.
Do you have voltage at the open end of the fuse on the left side( feed side)