Dash Lights Not Working

[mdeluca]

I'm banging my head against the wall here and hoping for some help.

NOT WORKING

• Speedo lamp
• Oil and volt gauge lamps
• Rectangular knob indicator lights have all stopped working.

They were working fine until about a week ago.

WORKING

• Headlights (Hi and Lo)
• Taillights
• Turn indicators
• Speedo turn indicator lamps
• Speedo emergency brake lamps

Using a test light with key switched to acc., I'm showing ground on both the + and - connections at each knob lamp (these are the rectangular night lights above each knob). I'm assuming that with the lamp connected to both the + and - wires, it would show ground on both terminals when there is no power.

With the battery disconnected and the + wire removed from the knob lamp, I show continuity to fuse.

I installed a new headlight switch (not mounted to dash - just hanging below) with no change. I did rotate the switch to make sure I wasn't dimmed down. I was told headlight switch did not need to be mounted to dash for ground in order for dash lights to work.

I've now ordered a PowerProbe III to inject power to various locations, but until it gets here I'd like to know if there is anything else I can check.



I was looking at the above Painless diagram and it shows an inline fuse for the dash lights. Does the OEM harness use an inline fuse and, if so, where is it located? That could be my problem.

The headlight switch connector was melted when I took it off. I've ordered a new one. The wires and all of the terminal ends looked fine. I plan on simply reinstalling them into the new connector shell.

 

[mdeluca]

Just to be clear... I'm working with the OEM harness.

 

[jzak]

Don't take this the wrong way, and I'm sure its not the case, but is there any chance you dimmed down the dash lights to the off position by turning the headlight knob counter clockwise?

Just looking at the simplest solution, before you gotta rip out all the wiring.

 

[mdeluca]

Don't take this the wrong way, and I'm sure its not the case, but is there any chance you dimmed down the dash lights to the off position by turning the headlight knob counter clockwise?

Just looking at the simplest solution, before you gotta rip out all the wiring.

Checked that first.. thanks.

 

[mdeluca]

Fixed!!!

Studied several wiring diagrams including the Painless diagram (which shed a lot of light on the headlight switch wire routing).

After getting the PowerProbe III, I was able to isolate sections of the circuit that worked and determine where I had power and ground. Unhooked the battery and checked all wires for continuity.

I finally found that I was not getting power to the double white wire terminal on the headlight switch. I applied 12 volts directly to the terminal with the PPIII and the dash lights came on.

Went back and checked all the fuses... all good... then I noticed an empty fuse slot. What the hell?!?!

I can hardly believe it, but the fuse apparently fell out of the fuse box (must have been loose because it was all working two weeks ago). Apparently it finally fell out... then got shop vac'ed up. I wasn't looking for a missing fuse because it was recently working and I hadn't removed any fuses.

Popped a new fuse in there and the dash lights came to life and I got a nice new tool out of the ordeal...

Bottom Line:

"Park & Tail" light fuse provides one of two points of power to the headlight switch. Both the "Park & Tail" fuse and the "ACC LPS" lamp fuse must be working for the dash lights to work.

btw... The Power Probe III is a fantastic tool.

 

[blackbrangus]

Having same problem on 83 CJ7, no dash lights anywhere. where is the inline fuse? wires under dash are a tangled mess. Pulling dash to try to sort it out. thoughts?

Thanks!

 

[Torxhead]

The later CJs do not have any inline fuses, if you do they are aftermarket. Good luck in your search. Bad grounds are a common problem, checking a circut with a fused ground wire can help. The wiring system in a CJ is color coded and tracing a circut down with a schematic really helps.

 

[Lumpy Grits]

Having same problem on 83 CJ7, no dash lights anywhere. where is the inline fuse? wires under dash are a tangled mess. Pulling dash to try to sort it out. thoughts?

Thanks!

:ww:
Cycle the dimmer control right to left on the headlight switch a bunch of times to see it that restores contact.
IF you do pull the dash-DISCONNECT the battery first.

LG

 

[jp360cj]

:ww:
Cycle the dimmer control right to left on the headlight switch a bunch of times to see it that restores contact.
IF you do pull the dash-DISCONNECT the battery first.

LG

Try this. My switch has a couple spots it loses contact for the dash circuit. For example, if I turn it too far to the left (near the brightest setting), the lights will go out before it gets to the courtesy light detent. When this happens, I have to turn the almost all the way to the right for them to come on, then back to the left to brighten them.