Stay with me here...

I've completed my wiring on a 69 that's going through a total resto. The original wiring harnesses were in good shape so they were cleaned up and installed.

All electrical components are working except for one strange problem. Both headlights work when the blue dummy "bright" light is illuminated on the dash,..but it's low-beam on the driver's side and probably low-beam on the passenger's side.

Then if I click the toe-switch (dimmer), the dummy light goes off, the passenger's side headlight doesn't work, and the driver's side goes to high-beam.

I disconnected the wiring to the dimmer switch and clicked it once thinking I could sync it up with the dummy light in the dash...didn't work. I tried a different lamp on the passenger's side and no change. I replaced the dimmer switch, and again, no change. I've strenghened the ground wiring and connections that run to both headlights, but no help. I've cleaned connections the best I could, but he problem(s) persists.

I'm out of ideas here. What else can I look for?

I don't own volt-meter...perhaps it's time.

Thanks in advance!

Sounds like a bad ground some where. For a quick test hook a set of jumper cables to the motor ( use both cables as ground) and battery & body. Test head lites....
Now take a test Lead (piece of wire will work in a pinch) and try grounding the dimmer switch, each head lite ect, test h/lites with each new connection. When they work correctly you have found the bad ground

Yep I agree with gene, bet its a ground somewhere. There is a ground tab wire on the pass side headlight socket that grounds to the rad. support, is that in place and clean/tight?

Bad grd, mine did the same. Its the ground near the washer bottle thats not getting a good enough connection. Also make sure the high beam/low beam switch is grounded to the floor well.

yep, I think it is the brown wire must be grounded to the body

Also make sure the high beam/low beam switch is grounded to the floor well.

The dimmer switch doesn't need to be grounded.

The brown wire is for the running lights. They are separate from the headlight circuit.

It does sound like a bad ground. Do the headlights appear dimmer than they should be? Just like a bad ground on the tail/brake lights, the current flows through the low beam filament when high beam is selected the same way it flows throught the tail light filament instead of the brake light filament when the brakes are applied.

Larry

(Here's another plug for my wiring diagrams)

http://hawkpichost.com/ims/album.php?u_id=47kT1HB

Thanks for the replies. I'll attack the problem this weekend.

Keep the suggestions coming.

A few more details for diagnosis:

1) The headlights are good and bright,..not dim or flickering.

2) I've already beefed up the ground and connections (to the radiator support) from each headlight with 14g wire so, I'm hesitant to believe I'm poorly grounded, at least at the headlights.

3) All other lights and electrical work great.

4) Again, with dummy light on "bright" I have low-beam from both headlights. Then after clicking the toe switch and turning the dummy light off, the driver's side goes to high beam and no light from the passenger's side.

I'll double check my ground with some jumbers,..if that doesn't work, what else should I look for?

Thanks again!

The only other thing I can think of would be that the tan and light green wires at the dimmer switch might be reversed. The headlight connector wires might be reversed instead, but both would have to been switched. That would give you low beam when the dimmer switch is in the high position and vise-versa. As far as the passenger low beam not working, if you already changed it out, then you need to see if you are getting power to the light green wire at that connector.


Larry

That's the direction I was leaning,..as far as the bright-light dummy-light problem, something somehow got reversed,..very weird because all I really did was clean the up the old harnesses and re-installed them.

And on the no hi-beam on the passenger's side, I agree,..since the headlights run in series, there's obviously a problem in the wiring/connections between the two headlights,..right?

Any other suggestions?..I'm listing them on a tablet.

Thanks!

,..since the headlights run in series, there's obviously a problem in the wiring/connections between the two headlights,..right?

No, they're in parallel. But your right, it could be the terminal at the passenger's light itself or the terminal on the driver's side where the green wire comes back out and goes over to the passenger side.

Larry

Review the way the wires are plugging into the back of each headlight. I had a weird problem with my bright indicator light coming on very dim when I just turned the lights on, but then would get bright (like it's supposed to) when I hit the bright switch. I just happened to notice the right headlight seemed to be actually brighter on dim than bright. Checked the wires on the back and yep...BUBBA had them wrong!!!

I changed the wires on the right light to match the left, problem solved. Sounds like you've got some similarities. I'm not sure if these cars are supposed to have a plastic "keeper" plug on the headlight connectors to keep this straight or not, but my car doesn't.

I figured this out, of course, after I dropped my column, pulled out the gauge cluster forward, loosened carpet and kick panel, etc... :angry: :angry:

Good luck with it, but that would be the easiest, quickest thing to recheck. Brian

Thanks 68vert,..I'm making progress. Yes, the green and tan wires in the connectors on the driver's side bulb were reversed. Big-time thanks!

But now,..I have both headlights working on low-beam. But when I click the toe-switch to high beam, my driver's side bulb goes to hi-beam, but my passenger's bulb side goes completely off.

I don't understand the wiring to the headlights. Do I have a problem with the tan wire that goes from the driver's side bulb to the passenger's?..or is it the green? Or do you guys have another idea?

Thanks again!

I know this is a stupid question but, Is the passenger hi beam burnt out? Try switching headlights to find out...just a suggestion...good luck...Mike

Yeah,..I tried a different lamp,...same results. Also tried a new toe-switch earlier in my diagnistics...the original was fine.

Does the green wire run the hi-beam and tan the low?...or vice versa?

Thanks

Light Green is the high beam and the Tan is the low beam. Black is the ground. On the dimmer switch the light blue is the power from the light switch in the dash.