Everything works but the headlights.

[johns68dart]

I have a 68 Dart, slant six, automatic that I am rebuilding. When I look at the wiring under the dash and in the engine compartment, I cannot believe this car is 45 years old. The wiring looks really good. Anyway, I got a new battery, all new bulbs, etc. and everything is working perfectly except the headlights. I just got a test light today and will check the power to the lights when I get home, but just wondering if anybody knows some weird tid-bit about this problem. I have an excellent wiring diagram of the whole car and checked everything associated with the headlights. Thanks in advance... John

 

[bcschief]

Check the head light switch it has a circuit breaker built into it for the head lights which commonly goes bad also check the dimmer switch it has a 3 wire connector 1 from the head light switch 1 to the low beams and 1 to the high beams it also commonly goes bad because it is on the floor a dirty wet environment also a possibility that both head lights bulbs are burned out

Brian

 

[johns68dart]

Thanks BCSCHIEF. I forgot to mention that I did get a new headlight switch and headlight bulbs. I did not think to check the dimmer switch on the floor. That is a very logical idea. Thanks... john

 

[67Dart273]

There are several main failure areas

As mentioned, checking at the dimmer is a VERY good place to start because this sort of divided the problem into major areas of trouble.

The headlights ONLY (not park or tail) are supplied UNfused power from the "in harness splice" coming off the ammeter circuit, which is a factory welded splice, taped up in the dash harness

The headlight switch itself has a built - in breaker which can fail

The light switch CONNECTOR can become corroded, loose, overheated and fail

So if you have power at the dimmer, you can ignore all of the above

The next trouble area is the bulkhead connector, but that of course would usually just affect either hi or lo beams, not necessarily both.

Last, after the harness goes through the bulkhead, there is a separate ground wire up front which grounds the headlight connectors. Make sure it is clean and tight. I.E. you could have power at the headlight connectors, and no lights.

 

[johns68dart]

Thanks 67DART273, I appreciate it. Like I said before, I put the new switch in over the weekend and it didn't help. The dimmer on the floor sounds like the likely culprit. Thanks... john

 

[johns68dart]

Thanks guys, it WAS the dimmer switch. I could kick myself that I didn't think of that. A $6 part after spending aout 6 hours looking for a short circuit....dang!!!

 

[cudajim]

Thanks guys, it WAS the dimmer switch. I could kick myself that I didn't think of that. A $6 part after spending aout 6 hours looking for a short circuit....dang!!!

It's not a "short" you were chasing, it's an "open circuit", in your case it sounds like an open switch.