Headlight will not work

[Joebee]

I have changed to wiring harness, the headlight lamp sockests, tried grounding them and they just won't work, I have parking lights, horn dash lights, brake light, but the minute I try the headlights I lose all the other stuff but if I rev the engine the other items come back on but no headlight. I have been fighting this battle for a while now and Had an earlier post about the problem but nothing seems to be working.

[Bob C]

What is the ammeter showing when these things happen?

[Joebee]

Well the ammeter reads charge before I try the lights but then it quits like everything els and when I apply the gas it returns with the other lights

[Joebee]

Yeah, I belong to the San Fernando Modal A Club. I have had a friend from the club helping but I think we have run out of ideas. maybe I will look to some of the other members ..... Thanks .... but still looking for anyone else with this problem or any ideas ......

[Bob C]

When you say the ammeter quits what do you mean, it shows 0 charge or
a discharge?

Bob

[Joebee]

Sponsored Links (Register now to hide all advertisements)

It shows zero

[tbirdtbird]

people from that club have gotta have some ideas. this is gonna be a tough fix from this distance.

did they ever work since you have had the car?
if so , have you done anything to them and if so, why?
etc

[Tom Wesenberg]

The Model A electrical system is fairly simple and should be pretty easy to fix IN PERSON, but can be difficult over the internet. We don't have enough information yet to know if the lights are shorting out, or there is a weak connection somewhere. I'd start by unplugging the left headlight, then try it. If it now works you know the problem is in the left light. Do the same with the right light, if the left doesn't fix it.

[Joebee]

Yes they were working until a month ago ...... I have had the car for almost 3 years ..... zOne of my high beam bulbs were flickering and then went out after I changed the bulb they stopped working ..... I bought new bulbs and it still does not work. I can't understand why all the electrical goes out when I turn on the regular headlights .... as i said the parking lights work ...... I even tried to change the wires from the parking light to the headlights with no results/

[Joebee]

And like I said since the problem I have replaced all the wiring the box at thaw end of the steering column the the headlight plugs

[Tinbasher]

Sounds like the wires inside of the connection at the bottom of the steering column are shorting out. Take the connection apart and look for burn marks on the casing. I would wrap the connections with electrical tape before you put it together as a oz. of protection.

Tinbasher

[700rpm]

If you have repro sockets in the lights, that would be the first place I'd look. They are notorious for creating problems in the lighting circuit, even if they worked before.

[Joebee]

Yah its a brand new harness and the old one I inspected thoroughly and check the new one one seeable burn marks

[Joebee]

no seeable burn marks

[Brentwood Bob]

There was trouble last year with the wiring harnesses. could be you have a bad harness. I had to do that about 6 months ago. Bob

[Patrick L.]

Have you put a test light/volt meter to anything ?
I would first suggest doing what Tom recommended. Try to isolate the problem.

[Tom Wesenberg]

Originally Posted by 700rpm

If you have repro sockets in the lights, that would be the first place I'd look. They are notorious for creating problems in the lighting circuit, even if they worked before.

Ditto what Ray said.
Check the headlamp sockets very carefully to see if one or both of the wire terminals might not be touching the metal ground. This is often the cause, especially if the repro terminals have too large a contact. If that's the case, then you can use a Dremel and grinding wheel to make the contacts a bit smaller in diameter. If the light bulb contact aren't the problem, the plug at the bottom of the shell may be the problem.

[jmeckel]

You need two things to start this project, an Model A wiring diagram, and a good volt meter.
Shot gun approches are never a good way to troubleshoot anything.
Start by studing the digram so you understand it.
Then take your voltmeter, connect one of the test leads to whichever battery post is connected to the frame (you have not stated if you are running positive or negative ground).
Now go to the switch at the bottom of the steering, check for voltage in from the battery side with switch off, if it is present turn the switch so the lights should come on, is the proper voltage still present? On the INPUT side? Make sure you are on the proper terminal by comparing it to the wiring diagram. If no voltage trace THAT wire back and find the problem.
If the voltage is good on the input, with the switch on, check the voltage on the OUTPUT side of the switch wich feeds the lights, look at the wiring diagram to make sure you are on the proper terminal, is the right voltage there? If not you have a switch problem. If voltage is present, follow the wire to the lights looking for cuts, splices.etc. then check the voltage at the socket, is it there? ?.... and so one. If you have voltage all the way to ONE side of the bulb and the buld does not light then you have a burned out buld or a bad ground. To fix a ground issue you start at the battery and make sure you have a good path all the way to the other side of the bulb. That is the only way to troubleshoot an electrical problem.

[Mitch//pa]

I also would get a simple test light to check things out.

[jw hash]

unhook the plug on the bottom of both head lights. now turn on the head lights if the other lights go off the problem is in the harness. but if they stay on it is in the head lights. now plug in one head light and check it again. I`m with Tom & Ray most not all the reproduction head light bucket wiring are JUNK. also look at the ends of the wires on the loom where they make contact at the bottom of the head lights, the wire connector ends should be flat on the ends not pointed like a male connector. if they are pointed they will have a tendency to push up between the inside connector. I have not seen one reproduction wire loom come with the right ends on them. Bratton`s sells the good ones part #20421 I solder them on.