Headlight switch problem

whb52ford

Senior Member
When I put on my low beams, both filaments light. When I put on my high beams, both filaments light.

I unplugged one headlight from outside the headlight where it connects to the bulb. Took the switch apart. When I jump from the power to low beam and check the bulb end, I have power to both wires. Same with high beam. I can't see underneath but wondering if that is the problem.
 

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Disconnect both headlights, you my have problem in the one that is still
connected and it is feeding back to the switch.
 
I have them both disconnected. Everything looks good. When I put it back together, now I have no lights, only the parking lights.

Is there anything I need to know on how to assemble the switch back together?
 
Following because I have the same exact issue. Not sure what is wrong but on every setting except for off all filaments light up. Running lights, high beam and low beam all on.
 
seems like somewhere someone has wired both low and high beams wires together use a jumper wire at the junction in the buckets and see if they light up separately
 
Did you have the retainer off the switch plate at the bottom of the column? Did you reinstall it correctly?
 
My guess is you have one/or both of the light wires grounded and the ground wire hooked up to the lights
Disconnect everything and start over, insure ground wire is hooked up first, then high and lo beams separately until you get it
Do you have a good electrical diagram?
 
Well I've traced it to the passenger side headlight. When I plug in the chrome conduit to the back of the headlight, both filaments are active. Unplug it and only have power to one wire, as it should be. Now, How do I get that headlight socket assembly out? Is it a pressure fit?
 
Well I've traced it to the passenger side headlight. When I plug in the chrome conduit to the back of the headlight, both filaments are active. Unplug it and only have power to one wire, as it should be. Now, How do I get that headlight socket assembly out? Is it a pressure fit?

See Brattons part #18270 even thought it says for sealed beam this is the one. The tab is inside the light bucket so you will have to remove the lens and reflector to depress the tab.

John
 
Check to see if the bullets on the wiring harness are correct. My car came with a reproduction harness that had the wrong bullets. They didn't fit correctly in the conduit connectors properly and caused a problem just like you describe.
 
The socket that holds the light bulb is the problem. Those two contacts are touching each other. So when the power goes to low beam, its also turning on the high beam. I have tried to stick a screw driver in there and separate them but they just pop back. I don't know how to keep them separate and let the bulb enter the socket.

I think I'm ok where the plastic plug is. All seems to be good there. I'm making contact because the bulb is lighting.
 
If the bulb socket contacts are touching each other you could try cutting a short piece of wire heat shrink sleeve and slide it over the contact so it insulates the sides but not the actual contact end. 1/4" sleeve cut to about 3/8" long should work. I used this same trick when the spring loaded horn contact inside the switch was touching something and horn sounded when the battery cable was hooked up. Just use the sleeve as is without applying heat to shrink it down as that might interfere with the spring behind the contact.
Kevin
 
My plastic plugs have two notches… The first notch is wrong and makes all three wires slightly offset. I just realigned to the second notch and the bullets all line up correctly now and lights function as they should.
 
I understand what you are saying, but the base where it enters the cardboard is ok. The tips are the problem. The wires entering the cardboard must not be at a 90 degrees, as the wires come from the base, they come together. I guess if I had the exact length heat shrink when I pushed the bulb in, the tips might go into the heat shrink and insulate them.

I ordered two from Snyders so hopefully this will fix it.

Have you bypassed that plastic plug tip that holds the 3 wires going into the headlight? Hard wired it. If so, how do you keep the chrome bezel on the headlight?
 
I just added a sleeve around the socket bulb contacts to prevent them from touching each other. Took me 5 minutes to do both headlights. Sleeve length was 5/16" to 3/8". One of the high beam bulbs had not been lighting, and though I did not detect a short before adding the sleeving, it works fine now. I removed the 12" headlight pigtail that connected behind the light bucket and hard wired after it shorted at the connector. The wide slot in the connector insulator does not hold the yellow wire end terminal as well as the narrow slots do, and that terminal was touching something to create a short.
Kevin
 

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I though i'd give it a try so I got some heat shrink and cut two short pieces. I could not get the bulb in. I made it shorter and still could not get the bulb in.

I decided to take out that cardboard piece. I took it out and it clearly was leaning to the inside. I took a piece of brake line and put over the terminal and bent it back out. Put it back together and it looks good. I plugged it back into the car and tested it without the bulb in. No cross feed. I have the test light on high beam for the other side and the steering wheel in low beam. The second I plug in the bulb the other side lights up. I'm getting the cross feed in the headlight bulb. I pulled the bulb and sure enough when I do a continuity check between both tabs, I get continuity. If I check each tab to ground, I get continuity. I'm totally confused now. I would think there should be no continuity between the two tabs.
 
I checked the bulb, and only one side lights with each tab on the bench.

This makes no sense to me. When I put the bulb into the socket, both filaments light.
 
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