I am trying to fix the headlights on a 1999 F250 superduty. They just all of a sudden quit working a few days ago but everything else works.

I have never seen headlamps this complicated. What gives with all the wires going back and forth between the two headlights and the firewall?

A good wiring schematic would do worlds of help. Anyone have any experience with this or the diagrams?

Thanks!

 

Does the vehicle have daytime running lights?
well lets see what you got .
I believe the 99 is wired the same as an 02 and I have schematics
There are 4 fuses
#7 30 amp #30 15amp
#46 10amp
#47 10amp
main sw
multi function sw on the turn signal

Do you have 12v on pin#3(db/wh) of both headlamp sockets when main sw is on and your in the low beam pos on the multi sw (turn sig)
in high beam pin# 1 (lg/bk) should have 12v on the sockets
will go from here and work back if you want
Rich

 

No running light on this truck.
I don't have any power to either light.
I do have power in the harness on the drivers's side. then it goes to a 6 wire harnes that t wires go to the dirver's side light and three gonear the passengers' lamp into another 6 wire harnes.

It's pretty weird, it's like the power goes by the driver's side light then is supposed tocome back from the passengers' side.

THanks for any help,
Dave

 

Did you buy the truck used?? Maybe the previous owner installed something similar to this...

It's a Headlight Upgrade Harness that's used to supply more power to your normally underpowered headlights.
__________________
2002 F-350 XLT 4x4 PSD 6spd SC SB SRW
2001 400ex SportTrax
1990 F-150 Lariat 4x4 I-6 5spd RC SB
---Also in Family---
2003 F-250 XLT FX4 6.0PSD TSA SC SB
2001 F-150 XLT 4x4 5.4 AT SC SB

 

I got it used. I thought about that but while tracing the wires I couldn't find any relays or extra fuses.

Looks neat though.

 

Dave,Have you pulled the main sw out of the dash yet ?

Do you have these color codes on that sw?
Dark blue/orange tracer this the pwr from fuse 7 30 amps 12v.its hot all the time.

Off the main sw you should have a red/yellow tracer wire on pin9 on the back of the sw. this is the feed wire out, when you have the sw pos on and multi sw on for head lights on low beam.
The dark blue/orange tracer also goes straight to the multifunction sw for high beams

After both wires leave the multi sw they go down to you fuse box .
one wire gy/orange tracer goes thru fuse #30 15 amps comes out as a lg/bk wire to pin #1 on both headlight sockets . High beam

The other wire Rd/bk goes to fuse 46 and 47, out of fuse 46 on a Db/wh to a connector back to db/og to left headlamp .

out of fuse 47 DG /og tracer to pin 3 of right headlamp.

Rich

 

Thanks forty,
I forgot to mention that this truck was set-up for plowing. I traced the power back into the firewall and found that it was the switch for the plow-lights/truck lights toggle.

Thanks again for all the advice!
Dave

 

Dave ,your welcome anytime thats what were here for !

Glad you found the problem!

Rich

 

Funny, I was going to ask if it was ever plowed with....your description of the wiring was exactly what I found when I ripped all my plow parts off my truck....
You can take all that wiring out if you want, and should be able just too hook the headlight plugs back on the headlights..as long as they didn't butcher anything

 

cool! I think I'm gonna do that!

 

Well if it was like my Western, the plow harness plugged into the right headlight socket to get its power, and the the rest of the harness plugged into the headlights.
The left truck plug was just left hanging..

I didn't have any sort of toggle switch though..when I plugged in the main plow plugs, it overrode the truck lights and lit the plow lights automatically