80L48

Last night all 3 groups of Instrument lights, Parking, and taillights went out (would not turn on). Both the instrument lights in Speedo/Tach and Center console are all out. Turn signals, Hazard, Brake, Headlights, High Beam indicator, courtesy lights still work. Fuses all look good.

I replaced the headlight switch a couple weeks ago and most of the bulbs are new.

With them all going out at once, I am suspecting that my new switch has gone bad or came unplugged.....

awesome71vette

It's very likely the plug on your headlight switch is burned up inside and not making a good contact with the 7 terminals on your switch. If you still have your old headlight switch see if any of it's terminals show signs of being VERY hot. If so the mating terminal in your plug is certainly melted.

80L48

The old switch actually worked, but I replaced it as I thought the Rheostat was causing the panel lights to be dimmer than thaey should due to being 36 years old. Everything worked before and everything worked after until last night. The headlight portion and the courtest activation (by rotating counter clockwise fully) all work, but the Instrument/Parking and taillights do not work at all. The turn signals and other indicator lights seem to work indicating that the ground contact is still good. It feels like the plug is still connected to headlight switch. (I can get my fingers on it after removing the AC duct, but I have not pulled the instrument cluster out.

Before I remove the Instrument panel and investigate, it looks like I'll order a new switch to replace (again)

Any other recommendations before I go down this path?

SwampeastMike

Substitute your old headlight switch before ordering another one. Hopefully you didn't throw it away

rdroket

I would double check fuses and even put in new ones before I took anything apart

Peterbuilt

The TAIL lamp fuse sends power to the INSTRUMENT fuse.
If the INSTRUMENT fuse blows only the dash lights go out.
If the TAIL lamp fuse blows both the tail and instrument lights will be out.

Replace the TAIL lamp fuse.
After you replace the fuse confirm power on both sides of the clips that hold the fuse.

If the fuse blows again post back for what to check next.

80L48

Gone, actually had to destroy it to remove as the **** release would not disengage, so I had to disassemble it from the back.

80L48

WOw, that was a great piece of insight! On mine that Tail lps fuse apparently feed all 3 (Tail lps, Parking, and Instrument)! I replaced it even though it appeared ood, and Eureka, everything is working!

Really appreciate that valuable piece of knowledge! Now to see if it lasts or if it a symptom of something else. I have no idea how old that fuse may be.