No cluster lights, running lights work
 

Car is an 88 n/a. Running lights and tails all work. I've swapped in and out 3 known good harness/headlight switch combos. I know this is a common issue with the running lights and interior lights both not working, so I want to reiterate that it's only the interiors not working. All fuses check out good also. Thanks!

The gauge/dash lights are powered by the Red/Green wire. This R/G wire can be found at the Cigarette Lighter. Does this wire have voltage w/the light switch turned to the first or second position? If it does not and the Illumination fuse is good then you can have a problem specifically w/the panel light control which adjusts the dimness of these lights or in general it is the switch which is problematic.

Is this likely after swapping several good switches? I just put the entire dash back together, I don't think its likely that I missed something but I'll probably pull it all apart tomorrow and start checking wires.

So basically, if I have voltage at that wire, and the fuse is good, it's definitely the switch?

What do I check if there's no voltage?

Also I totally forgot I already started a thread about this not too long ago. I was working on the car and came back to it after 2 or 3 months out of town for work.

If you have voltage at the wire then the switch is good and not bad. When the R/G wire connected to the switch comes out of the harness it passes down to FC-02 which mates the Cluster Harness to the Front Harness. It's possible that the connection at this connector is poor. The wire at the lighter should be accessible by removing the ash tray.

Is the wire still R/G coming out of the headlight switch? Asking because in case I don't have voltage at the cigarette lighter I want to jump the R/G to confirm it's the switch.

Yes. When my panel light contol unit failed I jumpered voltage from R/B (powers the tail lights) to R/G.

No voltage at R/G at switch. Jumping the R/B to R/G blows the illum. fuse. Connecting 12v to R/G from the battery makes the wire heat up. So looks like a short somewhere..

Edit*

Found it. I have 3 aftermarket gauges wired into that circuit. The bulbs seems to be drawing too much, or I wired them wrong.