Dimmer/lights wiring issue.

[igotatruck]

Hey all, I am having a weird problem that hopefully someone can help with.

A few months ago my dash board illumination lights and rear running lights quit working.

All other lights work correctly, save one dead headlight bulb.

 

I suspect it to be the dash dimmer module, as it once cut in and out as I wiggled it. Also the shaft just seems loose like the potentiometer inside is broken.

I would take it out and test it but I cannot for the life of me figure out how to get the knob off.

Any suggestions?

 

How get this knob off? vvvvv

[datzenmike]

If the rear tail lights are out also it isn't the dimmer. Both are supplied by the headlamp switch in the first position. It gets it's power from the 13th fuse from the left hand side of the fuse box. (3rd from the right) If your interior lamp is not working then this is the problem.

[igotatruck]

2 hours ago, datzenmike said:

If the rear tail lights are out also it isn't the dimmer. Both are supplied by the headlamp switch in the first position. It gets it's power from the 13th fuse from the left hand side of the fuse box. (3rd from the right) If your interior lamp is not working then this is the problem.

 

Do you mean the ceiling mounted dome light by interior lamp? That does work, however the headlight switch is sometimes reluctant to switch between hi/low beam so I really wouldnt be surprised if it was the culprit. 

 

 

[igotatruck]

Seems like it was the dimmer after all. The nut holding the pot got loose and cracked all three leads off. Gonna solder it up and test it at lunch.

 

.

[weldingrod]

I hate electrical!! At least hydraulics have the good grace to leak and give you a hint where the problem is. I am a welder and when everything is going good I have smoke, heat and flame. Apparently not so desirable when messing with automotive electrics.

 

Presently trying to find a noise in the front of my 1984 720 4x4, somewhere front of engine. Alternator rebuilt so that leaves power steering pump, water pump and belt tensioner. I guess best way is to remove one belt at a time and see when/if it goes away. Hopefully belt tensioner but we all know if you have dual wheels it is always the inside one that goes flat. Still trying to find a rear 43" driveshaft but found a driveline shop in town which can replace the splined slider, which is where the problem is.

[datzenmike]

The dimmer isn't responsible for the rear running lights. That must be something else.

[igotatruck]

58 minutes ago, datzenmike said:

The dimmer isn't responsible for the rear running lights. That must be something else.

Is there a relay on the running lights? Its shorted to ground somewhere.

[igotatruck]

1 hour ago, weldingrod said:

I hate electrical!! At least hydraulics have the good grace to leak and give you a hint where the problem is. I am a welder and when everything is going good I have smoke, heat and flame. Apparently not so desirable when messing with automotive electrics.

 

 

I have the opposite going on. I do electronics by trade and feel at home looking for cracked solder and bad wiring, but at a loss for making custom mounts and such.

 

Good luck nixing the noise!

[igotatruck]

Okay the problem was the 3 way switch Mike mentioned. A little rubbing alcohol and q-tips cleaned out the gunk on the contacts. Thanks to all for the help!