No power to cluster lights

[RobP]

I'm having issues with my instrument panel lights. Both my turn signal lights and the light that goes under the shift lens work, but the 3 lights that go into the instrument panel are not getting any power. Headlights work, brake lights, flashers and all other interior lights work.
The 3 dash lights were working intermittently yesterday when I reinstalled my cluster, but now they're not working at all (and getting no power). The lights that go to the a/c heater controls are also out now, but were working yesterday. Fuses look good, but I'm planning to replace them today just in case.
Any ideas?

 

[Dennis H]

Thumbwheel?

 

[RobP]

Thumbwheel?

Should have mentioned I bypassed the dimmer using this diagram:

 

[Sixpactogo]

If you disturbed the wiring harness under the dash, you may have pulled the three wire plug off of the instrument panel dimmer switch. You will want to check that and the fuse for the dash lights. If neither one of those are an issue, you have a broken wire or your dimmer switch may have failed. Most likely dirty connections on the dimmer switch

 

[Slotts]

The graphic shown is drawn incorrectly and would expect to blown fuse. That would send the 12 volts from the parking light circuit directly to ground.

The bottom is edited to show the correct wiring positions. This is only a band aid fix and will not allow your dash dimmer switch to turn on the dome light.

Test with an Ohm meter across the I and R terminals on your dash dimmer switch. This will probably show a o/l (open line).

Jim

 

[RobP]

Turns out it was the 3amp fuse. Now I need to figure out why it blew. With all the bulbs just hanging back there as I was trying to troubleshoot a ground issue, I wonder if that was the cause? Maybe they touched?

 

[bschomske]

My dash lights stay on .Could this be my dimmer also?

 

[Dennis H]

In this realm, it has been called thumbwheel. Dimmer switch historically refers to floor mounted hi-lo control.

 

[Sixpactogo]

In this realm, it has been called thumbwheel. Dimmer switch historically refers to floor mounted hi-lo control.

You need to be specific. There are two dimmer switches. One is the headlight dimmer switch and the other is the instrument or dash light dimmer switch.

 

[Dennis H]

Thus Thumbwheel. This may be a generational conversation. I'll stop.

 

[bigmanjbmopar]

LMFAO @Dennis

Why bypass the dimmer in the first place? Just so you don't inadvertently leave the dome on? Blown fuse for sure on that first detail.

 

[bschomske]

My question was the thumbwheel then...I used the wrong term..

 

[Shorthorse]

My dash lights stay on .Could this be my dimmer also?

No. The thumbwheel switch/panel light dimmer switch has no independent power source. It only passes power from the black wire of the light switch.

LMFAO @Dennis

Why bypass the dimmer in the first place? Just so you don't inadvertently leave the dome on? Blown fuse for sure on that first detail.

bigman, When the thumbwheel/dash light dimmer switch is bypassed properly, wouldn't the dome light switch action still work correctly because the dome/courtesy lights operate independently via switched ground, not +12V?

 

[440+6]

I jumped my dimmer years ago, now dash is full bright and dome light works normally.
There where no repos back then and my dimmer part of the switch sucked, this was my solution.