Troubleshooting lack of interior light when doors are opened. Turns out the solid brown wires at both switches are not, in fact, connected to ground. I can splice and make a new ground connection but want to find out what's wrong and make sure there are no other grounding issues I don't know about.

Before I start pulling things out from under the dash could someone tell me where, in general to start looking? The switch wiring harness sections are difficult to trace.

Thanks,

Ron

Click to view attachment

Up under the dash near the fuze panel

Doesn't the door switch ground via the screw? Been a time since I looked but you might look at this.

I repaired my buzzer lately and therefore checked the connections on the 4 pole door switches. For better understanding check with an ohm meter how the switches work. No ground via screw on the 4 pole switches! Either side (2 poles left/2 poles right) gives contact when the door opens and connects brown with brown (interior light) and red with red (buzzer on the fuse panel). Careful, one red wire has permanent 12V, so do not ground it. I additionally put shrinking tube over the red (+) connectors. Ground for the buzzer is applied via contact in the ignition switch when the key is in.