Got a problem with my 84 Bronco. Headlights will work fine until they heat up, then both low and high beams will constantly flash on and off. I will turn them off and let them cool, and they will work fine. Don't know what to do!

 

buy a new headlight switch. it has an auto shut off circuit breaker inside it-thats whats turning the lights on and off. when it is on a while it heats up and the circuit breaker turns it off until it cools down. i had 2 mustangs do this. kinda sucks when your driving home at night and your lights go out.

 

At least it lasted 20 years! I understand that there is also a way to change the wiring to include a relay that really brightens up the lights. Not exactly sure how to do it for the 84 Bronco, but I'm sure someone else can tell you.

 

I know this may sound weird but it may be worth a try... I had a similar problem with my pick-up and it turned out to be an intermittent short with the TAG lamp of all things... It had gotten water inside the lamp housing, somehow, and every now and then it would short out ...causing headlamps to flicker and eventually go out all together.... I tried everything imaginable (new lightswitch, new headlamps, voltage regulator...yada yada)

I then started ohming out the lighting system with voltmeter and noticed a direct short to ground...bad juju.. I isolated the rear lighting from the front at the light switch and found that the short was coming from somewhere in the rear lights. I eventually isolated the short in the TAG lamp, replaced the housing and bulb and BAM problem solved.

Not to assume you havn't checked all the lighting fixtures but it it may be worth the half hour or so to take out all the light bulbs (tail lights, tag lamp, front and rear turn markers) except the head lamps and give it a try...

Good luck

 

If you change the headlight switch, make sure you look at the plug. Make sure it's not melted, making a poor connection. Also make sure you don't have any extra lighting on the headlight circuit.

 

Thanks guys, the headlight switch did the trick! i can drive at nite without flashers now

 

Thanks guys, the headlight switch did the trick! i can drive at nite without flashers now

 

What is the exact location of the swith. I am having the same problem in my 97 expy

 

The article called "Whiter whites & brighter brights" about installing relays in the headflight system is in the "Tech Articles" section located near the top right of every page.
Here's the link to it...
https://www.ford-trucks.com/article/...r_Brights.html
RJDAVIS....They're talking about the regular headlight switch on the dash. I'd guess that the one in your Expy is the automatic type. My Town Car did the same thing with the automatic type switch & was more pricey to change than just the standard headlight switch.
AL.