Headlights come on with parking lights

[Jim Oaks]

1984 Ford Bronco II...

Replaced the stock headlights with LED headlights. These new headlights come on with the parking lights. Even weirder..... I can adjust the brightness of the headlights with the dimmer switch.

I want to say it's a faulty light switch, but the normal headlights worked.

The Bronco II has the display in the console that shows if a light is out. It was showing that I had a light out when I tried to install LED taillights. But it doesn't show a headlight out with the LED headlights. I thought maybe the problem could be associated with the wiring for this display.

I think I can overcome this issue by using the headlight wire to trigger a relay and feed the headlights from the battery, but I'm really bugged by this issue and trying to make sense of it.

Why are my LED headlights coming on with the parking lights, and dimming with the dimmer switch???

Would love to hear people's thoughts on this.

 

[97RangerXLT]

it definitely sounds like a bad headlight switch.

The only reason I can think of that it happens with the LED's and not the origianal sealed beams is that the resistance is quite a bit different with the new LED's that it is causing it to bleed through the bad part of the switch where as before it was not an issue.

AJ

 

[97RangerXLT]

Oh btw, those round LED lights look awesome on that B2.

AJ

 

[Uncle Gump]

I think the key clue here is that the headlamps are dimmable.

My guess is that the tell-tale system for the exterior lights has a circuit going to it for dimmable panel lighting. Somehow that circuit is feeding into the headlamps internally in the module.

I think I would just disconnect the tell-tale connector and see if it stops acting up.

 

[lil_Blue_Ford]

Man, that’s a good one…

I believe the tell-tail system feeds a small amount of electricity through each bulb to verify it’s not burned out. If I remember correctly from my 88, you had to hit a button for it to check and light up. Something is definitely amiss though. I’m kind of amazed that the LEDs are dimmable, most common LEDs aren’t unless you specifically buy dimmable. I wouldn’t have thought headlights would be dimmable.

I’d lean towards a bad headlight switch or some damaged wiring somewhere.