Dash Lights Intermittent Operation

[Jeff10]

Hi,

I have an problem with the dash panel lights (gauge cluster, primarily) not working when the headlight switch is pulled on. It's an intermittent problem, so I suspect that it may be a ground issue.

I know trying to chase down an intermittent problem is difficult. And I know there are lots of things that could cause the problem. I'm just hoping that maybe there's a known weak link for the problem that I might start with first. (I know the process may be a lot more involved.)

Has anyone else tried to troubleshoot a similar problem? Any solutions that you found?

Thanks for any advice you can provide.

Jeff

 

[Viperwolf1]

Sometimes the rheostat in the switch gets dirty. Exercise it a bunch of times and that should clean it. Also clean the contacts for the tiny fuse in the fuse box.

 

[Steve83]

Start by measuring voltage in one of the bulb sockets when the symptom is present. Leave the other affected bulbs installed & connected as normal. Put the meter's black probe on a good ground (which is an issue unto itself) and use the red to check each socket terminal's voltage. If they're both ~0V, then the fault is on the hot side of the circuit; if they're both ~12V, the fault is on the ground side.

 

[Jeff10]

Hi Phil,

Sometimes the rheostat in the switch gets dirty. Exercise it a bunch of times and that should clean it. Also clean the contacts for the tiny fuse in the fuse box.

It's good to hear from you. Hope you're doing good.

I'll try both of those when I can make some time to troubleshoot the problem. (I did try the working the rheostat on the switch when I brought the Bronco home last night... I only rotated it four or five times. I'll look at it again after checking the fuse holder. It might be this weekend.)

Take Care,

Jeff

 

[Jeff10]

Hi Steve,

Start by measuring voltage in one of the bulb sockets when the symptom is present. Leave the other affected bulbs installed & connected as normal. Put the meter's black probe on a good ground (which is an issue unto itself) and use the red to check each socket terminal's voltage. If they're both ~0V, then the fault is on the hot side of the circuit; if they're both ~12V, the fault is on the ground side.

Thanks for the input. I'll check it out.

Take Care,

Jeff

 

[B RON CO]

Hi, all the lighting grounds through the push on clippy part that holds the socket in the dash. I sometimes have to jiggle my left directional indicator bulb to make it work. If all the lights are acting up I would look for a problem at the feed, the headlight switch, wire up to the cluster or something like that. It could be the ground, but I think the dash will always ground through the 4 mounting screws. Anyway I think it is easier to play with the switch first. Good luck

 

[September 1972]

Yes riostat is suspect.

Electrical cleaner and spray the whole can at it while gently moving the riostat, to fast and you will snap the tiny wires, let dry and it might work. No lube!

 

[Jeff10]

Hey Guys,

Thanks for all the suggestions. I hope to get some time to troubleshoot it this weekend.

Jeff