Headlights On & Off & On, etc....

[PCTechman]

After driving for a while the headlights go on and off, and back on. Seems like it's a defective relay or switch. I don't find a short anywhere, and the lights do not go off when going over bumps. After a few minutes the lights go off/on when parked in the driveway, without the engine running, so I think it's a relay/switch problem rather than a short. All the connectors & connections check out OK. The headlight switch was overheating and it melted the modular plug where it plugs into the harness. I changed both the headlight switch & modular plug. Now it takes a little longer before the headlights cut out, so I guess I fixed part of the problem. The headlight switch seems to get hot, though it hasn't melted the modular plug. I bought a replacement headlight relay (gray), but I can't seem to find where it's located. After another member told me where to look, I located 3 of the same type of relays under the fusebox under the hood, they are green, tan and black, though. I'm going to remove each of those relays to see if the headlights go off when removed. When headlights are on they are both equally bright, not dim. Any other idea's? Anyone know of a different relay location or which of the 3 colors the gray one should replace? Maybe there's another relay/switch somewhere?

 

[biggeernie]

same problem

i have the same problem and can not figure it out so i hope someone czan help us.

 

[PCTechman]

Did you do anything in additon to what I did?

 

[Garbear]

I had the same problem with my 92, check and see if your headlight switch is hot to the touch, mine was and I replaced it cheap fix, problem went away

 

[PCTechman]

Did that twice! Still same problem....Thanks

 

[PCTechman]

Headlight Problem Still Not Solved

It's an annoying problem and I'm out of ideas:
After driving for a while the headlights go on and off, like it's a defective relay or switch. I don't find a short anywhere, and the lights do not go off when going over bumps. After a few minutes the lights go off/on when parked in the driveway, without the engine running, so I think it's a relay/switch problem rather than a short. All the connectors/connections are good. The headlight switch was overheating and it melted the modular plug where it plugs into the harness. I changed both the headlight switch/modular plug. Now it takes a little longer before the headlights cut out, so I guess I fixed part of the problem. The headlight switch seems to get hot, though it hasn't melted the modular plug. I bought a replacement headlight relay (gray), but I can't seem to find where it's located. After another member told me where to look, I located 3 of the same type of relays under the fusebox under the hood, they are green, tan and black, though and a member told me the 91's do not use this type of relay for the headlights. Any other idea's? Anyone know of a different relay location? Maybe there's another relay/switch I can replace?

 

[Garbear]

You might try replacing your headlight plugs in back of the bulbs, if the connection is not tight, it could cause your wiring to get hot. Gary

 

[dogfriend]

Wiring Diagrams here:

http://www1.autozone.com/servlet/Ui..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp

 

[PCTechman]

I replaced both headlight sockets (+2 9004 bulbs) when I first had this problem, they tested out electrically OK, but they were the Ford OEM pieces (read that 15+ years old!) and they were only 6$. I am thinking that the only other thing it could be is the integrated turn signal stalk, windshield wiper, headlight high beam module in the steering wheel. I was on my way home last night and I pulled the lever back to hold the high beams on temporarily, the headlights never blinked. When I put the stalk in the always on high beam position they went into their 30 second on/off routine like they do in low beam position. It's the only other thing I can think of that I have not replaced (unless I missed a relay or switch). It's a $100+ piece so I want to check everything else once again before I invest the money & time (looks like I'll have to pull the steering wheel to change it), especially if it's not the solution to the problem...

Did anyone else replace this module before?

Thanks,
PCTechman

 

[phs2911]

How do you replace a headlight switch? I just need to know the easiest way to get to the devil! I'm assuming I take off the entire cluster trim? And do you know a part number?

Nevermind. I found the part at Autozone for $27.99. Thanks!

 

[94xlt4x4]

this one drove me nuts in my b2..

turned out it was the high beam/turn signal switch shorting out..melting the modular plug..messing up headlight switches..and making the headlights flicker..

that could be your problem? it's at least worth a shot..

 

[CDW6212R]

That's a good suggestion, I was going to say the relay, which might be in the dash like 95+ models. Good luck,

 

[PCTechman]

:roll:

The 91's don't have a relay, so that's out. The turn signal, headlight switch dimmer, windshield wiper combo module is the only thing I did not change. On the 91's it's a one piece unit in the steering column and it's $100+ just for the part, but if it gets the job done....

 

[PCTechman]

Headlights Stay On.....FINALLY!!!

I replaced the turn signal, headlight, dimmer switch module in the steering column. Actually only a half hour job! The lights stay on 3x longer but continued to flash, but less frequently. The dash headlight switch was still getting hot even though I replaced it. So I installed a new switch and finally the problem is solved. The quality control of parts today is very poor and getting worse; the 1st dash switch I purchased was a Motorcraft branded piece and it was NFG right out of the box, the 2nd is Motorcraft also, but it seems to be a lot tighter and it works fine. I've had the same problem with thermostats, 3 different brands purchased from 3 different places and they all failed within several months!

 

[Turdle]

I merged your 2 threads into one for easier reference

 

[PCTechman]

Thanks....