Headlight Problems

[Crown Vicman]

Hey guys, I've been having these headlight problems with my 99 crown vic p71. I've been trying to put blue bulbs in my car but everytime I do they cause my headlights to start flashing on and off. So I end up having to change the headlight switch which correct the problems. The blue bulbs I tried are rated at 80/100 where as my stock bulbs are rated at 12V 65/55. Well later on I found some blue bulbs rated at 12V 65/55 same as my stock ones. I tried those and my lights still started flashing on and off. So now I have to go get another headlight switch. What am I doing wrong?:confused: Any input would be greatly appreciated.

[offroadkarter]

could it be a faulty relay burning out your switch?

[Crown Vicman]

could it be a faulty relay burning out your switch?

I don't think so because I can drive all day long with my stock bulbs on and nothing happens.

[Richy04]

There is a breaker inside the headlamp switch or in line with the headlight wiring harness which will (when the amperage is exceeded) open and when it cools it will close again. The visual clue will be the headlights going on and off as the lighting is exceeding the maximum current value set by the breaker.

To avoid this you must add a large relay in place of the headlights in the circuit and use the headlight line to trigger the higher current relay with its higher current source (like a direct fused connection to the battery) which will in turn supply the current to the higher amperage headlamps.

This is a simple circuit but it will take some time running the wires to the head lamps and adding fusing and making your own harness to do such a thing. The Ford harness ratings will not allow for those massive lights so you must use the headlamp line to trigger a more heavy duty circuit for your needs. Simply bypassing the headlamp relay or bumping up the breaker size will eventually cause a failure in the harness or light the harness up like a candle. Do it the right way or leave it alone. Richy

[RoyLPita]

Check the lighting control module. They had a TSB for the turn signals flashing fast intermittently. But the same module could cause your problem.

[cyclopsram]

Most states require a permit for any blue light showing to the front.

[jgc61sr2002]

Most states require a permit for any blue light showing to the front.

In New York State only volunteer firemen/women can use blue lights while respondiong to an emergency. The must obey traffic controls.

[offroadkarter]

I think he means headlight bulbs, not the siren lights

i think?