The hi beam indicator on my 1952 F-1 is bright on high beam and it gets dim on low beam.I thought it is just suppose to work when lights are on high?Do I have a problem with the wiring or something else?I am still 6 volt and when the lights are on dim I could do better with candles!High beam seems to light good.

 

I'd bet you have a bad ground at the headlights. It's back-feeding. Or could it be light from the instrument panel bulb leaking into the tube for the high beam? Try it on parking lights.

 

Hi Leon,

Ross is right in that you probably have a short. But your headlight bulb is grounded via a dedicated grounding wire in the plug on the bulb. This is becasue being all glass the bulb couldn't be gounded by contact with the bucket. That grounding wire should come out of the plug and be screwed to the inside of the headlight bucket with a sheet metal screw.

So,

If the ground were bad, neither the high beams nor the regular headlights would work at all (or they would both work marginally with a "limited" ground).

It sounds to me like you have a "slight" short on the wire that carries power out to the regular side of the headlight, and chances are it is shorted to the wire the highbeam indicator light is on, or in/at the connections for, the highbeam switch.

So, when you turn on the regular lights, some power is making it out there, some is going directly to ground via the short, and some is shorting through the indicator to ground. There has to be another source/place for that short to be occuring because that little tiny indicator bulb isn't going to channel off all that power and dim those two big headlights.

Check the wire going to the main headlight and your highbeam switch connections to see if some are touching each other or the switch case -that would also cause it to do exactly what you are talking about because the power shorting would also seek the ground the indicator light provides. Also, check the case of the Highbeam switch and the regular light hook up post for continuity. If there is, your switch is shorted and you'll need to replace it. It's a contact switch so the "generic brand 'X'" you can get a Kragen for 12 volt will work just fine- it's not voltage or ground sensative (ie positive or negative ground).

And lastly, don't drive it with those lights dim like that. With an open short, you are pulling a max amount of amps through the headlight switch, and I'll bet that sucker is getting VERY hot. Your circuit breakers too. If it does, it will melt the "bakelite" (plastic) that holds the wire posts in place and ruin the switch.

Good luck,
Julie

 

Hi Leon,

Ross is right in that you probably have a short. But your headlight bulb is grounded via a dedicated grounding wire in the plug on the bulb. This is becasue being all glass the bulb couldn't be gounded by contact with the bucket.

If the ground were bad, neither the high beams nor the regular headlights would work at all (or they would both work marginally).

It sounds to me like you have a "slight" short on the wire that carries power out to the regular side of the headlight, and chances are it is shorted to the wire the highbeam indicator light is on, or in/at the connections for, the highbeam switch.

So, when you turn on the regular lights, some power is making it out there, and some is shorting through the indicator to ground. There has to be another source place for that short to be occuring because that little tiny indicator buld isn't going to channel off all that power and dim those two big headlights.

Check the wire going to the main headlight and your highbeam switch connections to see if some are touching each other or the switch case -that would also cause it to do exactly what you are talking about because the power shorting would also seek the ground the indicator light provides.

If you take your headlight out, and unplug the plug this is how it is wired if you are looking at the face of the plug:



And lastly, don't drive it with those lights dim like that. With an open short, you are pulling a max amount of amps through the headlight switch, and I'll bet that sucker is getting VERY hot. If it does, it will melt the "bakelite" (plastic) that holds wire posts in place and ruin the switch.

Good luck,
Julie

 

Other than the ground you may also have both high&low beam wires hooked to your high beam indicator light...

 

Good point Jaye! I guess sometimes we look too hard at the possible complex problems to site the obvious - DOY on me!

Sorry about the duplicate post. Anyone else finding the site a little weird this weekend?

J!

 

However, on second thought if you had both high/low beam wires attached to the high beam indicator the light should still be bright, sooooo back to the ground possibility.

 

Yeah - lots of possibilities here. But if it were my truck, first thing I'd do is replace the high beam switch and check the wiring there. It sounds like it's "Dragging" a little internally. If that's not it he has to have a short in his wire feeding the regular beam.

J!

Electricity is VOODOO!

 

I changed the dimmer switch and that did not help.I guess the wiring is shot or I need to get a new headlight switch?I have good high beams but my lows are worthless.Of course I realize I am only 6 volt!

 

Could be, but before you rewire, pull your headlights out and check to make sure those plugs are wired correctly. You might have the ground and high beam swapped on one of them. Chances are also that your low beam wire has a bare spot and is touching ground - probably right at the hole where it goes into the headlight part of the grille or th erubber grommet in the back of the headlight bucket.

Your headlight switch is ok.

Electricity - VOODOO!

J!