48 DeSoto. Converted to halogen. Just recently, passenger side hi beam does not work. Driver side, everything works as it should. Replaced bulb, still no hi beam, PS? Is single light, bulbs are hi/lo beam all in one bulb. Jack
Does the light stay lit between low beam and high beam, or does it go out on high beam? If you were able to install Halogen lights on your 48 DeSoto, am I correct in thinking the wiring has been redone and that you have converted to 12 volt neg ground? If the light stays lit but the brightness doesn't change, my guess would be you have a ground issue. Some wiring harnesses will have both headlight ran through a common ground. I'd rather see them each grounded separately. Gene
I would guess that the high beam wire at the dimmer switch is loose or not connected at the dimmer switch. sorry....missed the part where it’s only one, not both high beams not working.
The power wire from the dimmer switch for both low beam and high beam both split to go to each side, one of the high beam wires could have easily broken, but if that was the case, he would not have any light on the one side. If he has light, but its not brighter, the issue is most likely someplace else. Gene
EXACTLY! The wire usually runs out from the dimmer switch to some sort of terminal block on the inner fender or core support where one wire runs to the left headlight and one runs to the right. A test light or volt meter will tell you which wires are low beam, which are high beam and another set to park lights. There may also be another wire for the horn (s). Since the left works and the low beam works your issue is going to be in the wire running from there to the passenger side headlight.
How do I check it with only a test light? I have feeling it is the female connector. Have been looking at connectors, and they range from 2.99 Dorman to 59.99 Standard????
Remove driver’s side horn for better access to headlamp junction terminal. My original cloth covered wiring was especially crappy in that area causing similar issues. Sent from my iPhone using H.A.M.B.
Also , if staying with 6 V don’t use anything smaller than 16 gauge wire for the headlamp wires from junction block to sockets. I went with 14 gauge on my 47 desoto and park, turn , and headlamps are back to normal Sent from my iPhone using H.A.M.B.
Hook the alligator clip of the test light to ground - some handy bare metal part of the body within reach. Disconnect the affected headlight. Turn the lights on. Hit the dimmer to lo beam and insert the probe end of the test light in the connectors, one at a time. The one that lights up is lo beam. Of the other two wires, follow them to the end if it is not too far away. If it ends in a ring lug to the body sheet metal, it is the ground wire - the remaining wire will be the high beam wire. If it lights up in the high beam position, the problem is with the headlight. If it does not light up, that is where your problem lies. Follow the wire to where it is broken or disconnected.
I've had a lot better luck upsizing the ground wire in the socket and running it to the frame not sheet metal.
I replaced the female light connector. It fixed the problem. I used the Dorman connector, what a piece of crap that is. When you live in a rural area, not many options available. I am going to replace the Dorman with a better product. Thanks to everyone for your help.
Figured out and fixed, til I can find something better than that piece of Dorman crap. Lotta pictures of some fine iron at the Deuce Doings.