Tonight I backed my 72 duster out of the garage. While backing out the engine died, so I started the engine again and my headlights went out and haven't come on since. The fog lamps and accessory lamps come on but the headlights won't come on at all. Any suggestions on what I may have done this time?

Thanks,

Jon

 

it my be your dimmer switch.try turning on the high beams thenswitch back to your low beams and see if they work. my car does that every once in a while.

 

Check for the obvious blown fuse first.

 

The headlights should NOT be fused, they should be on an auto-reset circuit breaker. I would check the dimmer and/or headlight switch.

 

Thanks for all the help guys, I have cleaned all of the wiring harnesses that plug into my firewall, I checked the fuses, which I now know they aren't fused, I also hit the dimmer switch repetitively, and have had no luck yet as to getting my lights on low beam to come on. My next venture will be to check the switch. Thanks guys again and if you know of anything else I could do I would appreciate it!

Thanks!

Jon P.

 

Time to get a test lamp and do some checking.

The power for ONLY the headlights (not park, tail, or instrument) comes from the WELDED IN HARNESS SPLICE which rarely, but can, fail.

This goes to a circuit breaker in or on the switch, and the breaker can fail

The switch can fail, you can have a bad connection at the switch connector

Could be the dimmer itself

THE DIMMER is where I'd start because it is easy to get to. It is simply a "two way" (SPDT) switch, so headlight power goes to the switch, so one terminal is ALWAYS hot with the light switch on, and one of the other two is hot depending on high or low.

 

This evening I took my dimmer switch out and used a test lamp and tested all three prongs, they checked out fine. I also checked the three wires running into the switch. They checked out fine too, so now I'm going to check the switch itself. Any more ideas would be greatly appreciated! As always, thank you!

Jon

 

Where would the welded in harness splice be located?

Thanks

Jon P

 

Do you have POWER at the dimmer switch? As siad. one terminal will be hot at all times with the head light switch. One of the other 2 will be hot depending on high/low position.
If you have power at the dimmer, next check at the head light for powerand if there is, you have a GROUND problem.
http://www.mymopar.com/downloads/1972/72ValiantA.JPG

 

VERY good point

You said "checked" the wires and they "checked out fine."

I do not understand what you mean, there.

What you want to do is, hook up the dimmer switch to it's harness, turn on the headlight switch, and see if there is power on TWO of the wires

If you only have power on ONE, the switch is bad

If you have power on TWO, actuate the dimmer switch, and power should appear on one of the original two, drop OFF the other of the original two, and APPEAR on the formerly dead terminal

If that happens, you have a bad ground up front in the headlight harness. Somewhere up there is a wire coming out of the harness, going to a ground bolt.

If you do not have power at ANY of the three dimmer switch terminals, you have problems up at the headlight switch.

You know how to remove it?

The **** does NOT come off. Disconnect the battery ground, pull the headlight switch to full on, reach up in and feel for the button in the photo below, "click the link." Push in the button, play with it and the **** a little, and the **** and shaft should come out. Then you can remove the nut.

http://lammon.com/abodies/SDC10657.JPG

This would be easier to get to if you decide to remove the instrument cluster You have a shop manual? You can download one for free here:

http://www.forabodiesonly.com/mopar/...al%2C+download

Also, there are useable diagrams at MyMopar:

http://www.mymopar.com/index.php?pid=31

the two diagrams

http://www.mymopar.com/downloads/1972/72ValiantA.JPG

http://www.mymopar.com/downloads/1972/72ValiantB.JPG



Leave the welded splice for LAST. After we determine whether you have power or not at the headlight switch, because you'll have to pull the harness apart to find the splice.

 

Last night I took the dimmer switch out and used a continuity tester on the dimmer switch. I tested the switch so that I had hot prong in the middle and on one side, then I pressed the dimmer and then tested again, so that then I had a hot prong in the middle and a hot prong on the opposite side of the first testing. The dimmer switch seems to be working like it should, right?

Tonight I will look for the ground wire running to the ground bolt to see what I can find there.

Once again guys, I'm new at this, 23 years old, so I'm pretty green at this stuff, thank you all for your patience, time and your information, I greatly appreciate everything you've offered.

Thanks again guys,

Jon P.

 

You are correct after checking in my service manual it is a auto-reset breaker.

 

Alright guys, the verdict is in. I took a long shot in the dark(no pun intended) and bought a new headlight, I checked my ground just to double check to see if I had good ground and I did. I then replaced the old headlight with a new one, hit the light switch and there it was, the prettiest thing I've ever seen, a light came on, on low beam!!!!!

I checked the other light and the same thing, so it looks like the culprit to no lights on low beam was due to both lights blowing the low beam bulb, it sounds crazy I'm sure but it happened!!

Guys, thank you for all your help and input! I greatly appreciate it!!

Jon P.