Classic Mustangs (Tech)Technical discussions about the Mustangs of yester-year.
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So I have some questions on my headlights. Awhile back, they were dimming low then going back to normal brightness. I replaced my voltage regular, and the problem went away. Then the motor was rebuilt, so the regulator/car wasn't being used. Once my car got back on the road, I noticed that now the headlights are going from normal to really really bright, but only during speeds 40+ mph.
When they go bright, its so strong that I'm worried people think I'm flashing my high beams at them. In fact, I didn't even think they could get that bright because as long as the car has been in my family they have always been sub-adequate in terms of brightness. I can imagine 4 possible problems:
1) voltage regulator was bad and/or fried
2) I have read that headlight switches go bad...maybe that's it?
3) old headlight wiring harness? not too sure about this
4) the alternator didn't get replaced...coincidence or culprit?
My lights are stock, not upgraded or anything. I have a basic stereo and my alternator puts out enough amps to cover everything. However, the alternator is NOT new by any means. What things should I look out for? The wiring harness didn't have any obvious signs of issues, but I know finding problems with wiring is like finding snakes in grass.
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It is possible that it is the headlight switch or dimmer switch. First though, you need to get a voltmeter on the battery and look at what the voltage is at around 3000 rpm with the headlights on and off. If its all over the place it may also be the V reg.
jlg2002: you are making me think it is the headlight switch, because come to think of it one of my dash bulbs burnt out recently...definitely going to order a new switch... I'll do that voltage test and update results.
The stuff you buy at Autostoned or the like will more than likely be Chicom crap. Maybe check Ebay for an NOS unit. I bought one for 50-60 bucks but I figured it was worth it after I replaced crappy headlight switch after crappy headlight switch, (about 3 in 2 years) until I went NOS and it's been over 5 years with nary a flicker.
One and done.
Governments are extremely dangerous.
Death, imprisonment, theft of property
and loss of freedom will result from
giving them too much power.
Once you get your lights working properly, consider installing some relays. I have thus setup. You can also make your own. It will take the load off of the switch as well as supply more voltage to the bulbs giving you brighter lights.
If they're blinking off and on intermittently, I'd agree about the switch.
But you also said they're going brighter than they ever have before. That can only be caused by high voltage at the headlamp and THAT can't caused by the switch. The switch can reduce current through high resistance contacts, but it certainly can't manufacture any more volts. I know you checked your battery voltage but still, my bet for the overly-bright lights is an intermittently sticking cutout relay in the regulator (I'm assuming it's an electro-mechanical regulator, not a solid-state unit).
I have to replace the dash light bulbs anyways, so doing the headlight switch at the same time isn't too much extra work it seems. I have a regular stock external regulator, and the lights DID use to dim (they do not anymore...). I figure eventually I will want to slowly rewire my car so doing the switches now saves me any future hassles.
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