67bearfury
New Member
All of the lights on my car work, except for the dash lights. Bulbs are all new but arent getting power. (tested the wires) Any ideas? Possible wire problem? Thanks.
1967 plymouth fury dash lights?
- Thread starter 67bearfury
- Start date
Dimmer control on your headlight switch?
goldfish65
Active Member
Usually you can work the thumbwheel back and forth and presto you'll find a spot where it gets a good connection.
67bearfury
New Member
I tried but theres no spot.
67bearfury
New Member
What do you mean?
Some cars have a dimmer control on the headlight switch which over time fails due to corrosion buildup. They can be cleaned with Deoxit or similar product - requires removing the switch from the dash and cleaning the contact and dimmer coil.
Clover
Well-Known Member
There is a 5 amp fuse in the fuse box, for the dash lights. Make sure that it’s good. If it is, it’s most likely the dimmer switch that’s bad. There are other possible causes but they’re unlikely.
You can bypass the dimmer switch with a wire to see if that gives you dash lights. Or if you are not comfortable doing that, a test light to the load end of the circuit will tell you if there is power. It should change in brightness as the thumb wheel is turned.
Dave
Dave
Where do the instrument panel lights ground?
The panel light dimmer is a simple rheostat. Perhaps no continuity in it?
The OTHER thing is the little tangs on the sides of the light sockets. Are they new or in otherwise good condition? But that wouldn't take all of them out, just the affected ones.
Just some thoughts,
CBODY67
The panel light dimmer is a simple rheostat. Perhaps no continuity in it?
The OTHER thing is the little tangs on the sides of the light sockets. Are they new or in otherwise good condition? But that wouldn't take all of them out, just the affected ones.
Just some thoughts,
CBODY67
Gerald Morris
Senior Member
Check first whether you have voltage of any sort from the headlight switch to the instrument panel. That should go up to the full voltage of your battery/charging system. Then look for a "voltage regulator" ON the instrument panel, likely grounded to the fuel gauge. This is an electro-mechanical thermal point device which opens and closes often enough to give you half of your system voltage; normally about 6.5 VDC. If NONE of your instrument lights work, then there is a good chance your old "voltage regulator" has DONE YOU A FAVOR AND DIED! Go buy a solid state 5 VDC power supply w a 12 VDC input, good for say, 5-10 amps output and feed your instrument lights off that if you really want to keep the old incandescent bulbs there.
If the headlight switch isn't passing current to the instrument panel, then first verify that its getting the current allocated for that purpose from the fuse box. If so, replace the headlight switch, or fix it. I replaced mine but kept the MoPAR original, as its vastly superior quality to the replacement warrants a future cleaning. There's a wiper which sweeps over a coiled resistor on much of the circumference of a big ceramic wheel in the switch. That's how folks varied DC voltage 50 yrs ago. This connection can be cleaned to restore current flow to the instrument panel. I'm lazy and oft pressed for time too.
That excrescence behind your fuel gauge, the "voltage regulator" is a very likely culprit. Be sure also that the breadboard which all that stuff plugs in to back behind your speedometer is WELL GROUNDED! A floating voltage with no good ground won't light so much as a tiny LED, let alone those primitive thermo-electric bulbs. Does your fuel gauge work? If not, then look at that regulator for sure!
If the headlight switch isn't passing current to the instrument panel, then first verify that its getting the current allocated for that purpose from the fuse box. If so, replace the headlight switch, or fix it. I replaced mine but kept the MoPAR original, as its vastly superior quality to the replacement warrants a future cleaning. There's a wiper which sweeps over a coiled resistor on much of the circumference of a big ceramic wheel in the switch. That's how folks varied DC voltage 50 yrs ago. This connection can be cleaned to restore current flow to the instrument panel. I'm lazy and oft pressed for time too.
That excrescence behind your fuel gauge, the "voltage regulator" is a very likely culprit. Be sure also that the breadboard which all that stuff plugs in to back behind your speedometer is WELL GROUNDED! A floating voltage with no good ground won't light so much as a tiny LED, let alone those primitive thermo-electric bulbs. Does your fuel gauge work? If not, then look at that regulator for sure!
Clover
Well-Known Member
I must point out that the 5v regulator on the cluster has nothing to do with the dash lights. They run on 12 volts. Most of the gauges use the 5v supply. That’s it.
Gerald Morris
Senior Member
OK, wasn't sure if it was just the dash lights or if the cluster was involved. Thx 4 the clarification. There is a constantly on 12V circuit, red wire, which also feeds the brake lights that feeds the map lights and the glove box. The dash lights are fed by an orange wire I believe. I need to replace all my dash lights, and probably will use LEDs when I do. The radio and heater had working connections to their respective lights.... Its been about 6 months since I was last in there.
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