Hi-Beam Headlight Problem

Tony,

If you haven't already, check this schematic from SOBill, courtesy of panteraplace.

I assume you have checked all fuses with a meter?

Is your indicator light - the blue one - coming on?

Have you checked and cleaned your ground wires up at the lights?

Larry

I'd be curious as to what you find out. On my car, the High beams stay on all the time and will not kick down to the low beam. Also sometimes me directionals won't work unless I hold a little pressure on the Hazards button. I haven't spent much time on her yet, but I plan to in the next few weeks.

Any information would be helpful.

Thanks

George

quote:

My next guess would be the hazard switch

The headlights do not go through the hazard switch, but the turn signals do.

John

quote:

Also sometimes me directionals won't work unless I hold a little pressure on the Hazards button.

That is a very common problem, and a very common solution.

What some owners do is gently wedge the button in the right position, using a toothpick or something similar.

That switch has an absurd number of wires going into it. If you attempt to check or replace it, pay VERY close attention to which wire goes where, double checking each wire color and position.

As for your high beams, some owners jump the wiring to give both beams at all times. As a first check, I'd check for such jumpering on your car.

Diagram is for late cars. See panteraplace for the early version.

Larry

Tony,

As Larry asked, is your high beam indicator light coming on? If so, then the fuse to the driver's side high beam is good and there should be voltage at the headlight bulb. Pull the headlight bulb and check for voltage.

It's possible that both headlight bulbs are bad.

John

quote:

sometimes me directionals won't work unless I hold a little pressure on the Hazards button

George S,

This may be a warning that the hazard warning switch's latching mechanism is about to fail. If/when it fails, the button pops out and the warning lights start flashing. This could happen at any time and could leave you with a dead battery. You can do as Larry suggested and wedge the button with a toothpick. A straightened paperclip also works for a quick fix.

If I were designing that hazard warning switch, I would design it so that if/when the latching mechanism failed, it would fail in the "off" position, not the "on" position. My .02.

The hazard switch is a bit of a PITA to change, but it's not that bad. New switches are ~$75, but the early switch is replaced by the later switch.

The early hazard switch does not have the word "HAZARD" on the button and does not have an internal light that is connected to the instrument lights (via the dimmer). You can change the red button easily. It unscrews easily by hand.

The later switch has a terminal 59d (instrument panel light) and the early switch does not. Don't connect any wires to this terminal if replacing the early switch with a later one.

The early switch has a terminal 30b and the later switch does not. Don't connect this wire if replacing an early switch with a later one.

Disclaimer: This info is from memory, and that's a little fuzzy these days...Ahhh, what was I talking about? Guess I can't remember.

John

Assuming the hazard switch is about to go, the main problem is the internal spring pressure for the pop-out switch button gradually distorts the switch body. The latching mechanism has a pin inside that runs in a groove, allowing the system to function as a cam. It's possible to remove the switch, disassemble it and wedge the cam-follower inside so it more closely follows the slot cut in the switch body; I did this decades ago using a strip cut off an old Hall Pantera business card!
Others have had good luck adding a small worm drive HOSE CLAMP around the body. With this fix, you play with the button position and hose-clamp tightness until the follower and plastic body are in their proper places again.
It's also possible to adapt a hazard switch from a '70s Alfa Romeo, but the switch's wire designators on the back are not identical to your Pantera. There's a Nov '08 POCA Newsletter article describing this method.
Finally, the OEM haz-switch is one of a number of parts recently reproduced by Santiago DeTomaso and Steve Wilkinson, and the 'real thing' is fairly cheap from vendors now. I assume it comes with instructions.
So there's really no reason to put up with a malfunctioning hazard switch. Wedging the button with stuff is hazardous- push too far in and it disconnects your brake lights, which will earn you a fix-it ticket which is not free anymore- in cash-broke CA anyway, I'm told the DMV charges up to $200 for such.

Dear Tony,

My '74 Pantera #7191 had the same problem: no high beams. My mechanic tracked down the problem: factory incorrect wiring resulting in an improper connection at the socket for the highlight bulb. Problem found. Problem corrected. Now I've had low and HIGH beams for eleven years. Good luck chasing down the electrical gremlin. FWIW.


Chuck Engles

quote:

I assume it comes with instructions

The hazard switch that I got from Wilkinson did not include instructions.

John

Did you ever get to the bottom of this?

Actually, I haven't fixed it yet. In my defense, I've been on business in China.

It seems possible that both hi-beam bulbs are shot or there is a ground connection problem with both. However, I think thats unlikely.

My biggest clue is that when I turn on the hi-beam lights via the stalk the blue indicator light on the dash does not engage. Maybe this is because of a bulb/ground problem and the circuit is not being completed but thats not my opinion. I just replaced the stalk and both stalks behaved the same which makes me think thats the issue. I also noted with the hi beams engaged that I'm not getting any power at the fuse (in o or).

Thus, my latest theory is that the headlight switch is not wired properly. I took it out myself and used trial and error on the 5 wires into it. I must have made a mistake. However, everything else works fine, parking lights, headlight motors etc.

Any words of wisdom ?

Thanks,
Tony