anyone?
I'll even entertain stupid ideas at this point

 

Check air pressure in tires? Fluid in Brake resevoir still full?


Seriously.
Sounds like a wiring issue. I don't think there is a fuse for that, but, you could check that?

 

you need a hammer....

 

Sounds like your dimmer windings/sweeper is shot. time for a new switch.
Robb

 

:stupid

 

I had this bookmarked.. maybe it's your problem too?
http://fullsizebronco.com/forum/showthread.php?t=87363

 

Pressure and fluids are A-OK (wiseasses)

No fuses that are doing it-as they DO work, just gotta fuss with the switch

Gots a hammer, and I'm ready to start using it on the damn truck just out of sheer frustration

As far as the dimmer/sweep idea--it is a new switch, although I suppose it could be FUBAR, since it's from Vatozone

Checked that thread you linked to; actually found it earlier when I was trying to get this figured out--no charring on my harness, and all the wires appear to be snug in the connector.


Latest update; I just noticed that the parking lights are right along with the problem, so it's almost like the internals of the switch are tits up
Gonna consider taking the old one apart just for my own benefit--see if I can figure anything out

 

I'm having the same issue. This is my second harness and second switch and they're doing the same thing. Don't really see how it can be wiring since when you jiggle the knob around it makes the headlights and tail lights come on.

I'm at a loss here:banghead

 

Could very well be another garbage switch. The aftermarket headlight switches are extremely poor quality compared to Ford OEMs.

I'd see if you have a pick n pull near you and pull a Ford one out of an F series truck.

Have you done this with the entire harness pulled out to see that the jiggle is definitely messing with the switch and not wiring further back?

 

Check any used switch for burning. Once you get a switch that works, install a headlight relay kit to keep the switch and harness from burning out again - Ford did not install headlight relays and ran all the current through the not-very-robust switch.

 

9 year old thread revive

 

Yo,
Where there is smoke, there is...
Switch Fires, Part Number SW-2103: "...Over the past two years, this office has experienced fires caused by another potential problem in Ford vehicles. The problem exists within the dimmer portion of the headlight switch in Ford vehicles. The light switch involved is a Model SW-2103. These are the pull out type headlight switches usually located in the lower left corner of the front dash of Ford vehicles. The headlight portion of the switch has two pullout positions, the first for parking lights only, and fully out for headlights and parking lights. The shaft of this pull-out light switch can be turned clockwise and counterclockwise which activates a dimmer switch, lowering and raising the intensity of the lighting in the instrument panels respectively. Fully rotating the shaft counterclockwise past a notch activates the interior lights within the vehicles. The potential problem exists within the dimmer portion of this switch. The dimmer mechanism consists of a metallic resistive coil set inside a ceramic disc positioned over the shaft of the switch. The coil is exposed on its front side away from the passenger compartment. The front side of the coil passes across a contact permitting a current to flow through a certain portion of the coil when the switch is pulled our in its first or second positions. The greater amount of coil through which the current is permitted to pass (clockwise most position) creates the greatest resistance and therefore dims the dash lighting to its lowest intensity. The opposite position provides greatest intensity. Through our investigations, we have found that the coil can fail owing to wear and/or possible material defects or damage. A fractured coil can maneuver itself free of the ceramic disc permitting it to come in contact with the metal bracket which mounts and grounds the switch to the vehicle. When this occurs, a current can flow through a portion of the coil creating high temperatures melting the metal material of the coil and possibly igniting surrounding combustibles. This mechanism has been observed in three separate incidents by this office. Two of these resulted in a fire. The mechanism is precipitated by wear and/or defect in the coil mechanism. If the former is true, we expect there will be an increase in fires caused through this mechanism given an increase in service time. To this date the problem appears to be somewhat limited. However, this particular light switch has been utilized in numerous Ford vehicles. Therefore, a small increase in failure rate owing to age and wear could result in a significant increase in fire losses. The SW-2103 Light Switch Assembly discussed above is reportedly installed in the following Ford vehicles: 1986 -1997 F100, F150, F300; 1990-1994 Explorer; 1987-1994 Ranger; 1987-1990 Bronco II; 1992-1997 Aerostar..." Miesk5 NOTE: No Bronco Listed, but this may be the result of typos or incomplete research by the company.
by waltersforensic.com
Miesk5 NOTE: No Bronco Listed, but this may be the result of typos or incomplete research by the company. Also, some small privately owned parts stores may still stock this defective switch. If any unusual exterior or dash light problems occur with symptoms such as intermittent dash lights, intermittent radio, trailer brake constantly beeping and both the marker lights and headlights would work, only not at the same time, pull switch and inspect it, the connector and harness. Reports that new switches are fine, but symptoms occurred because PO or shop removed original defective switch, but connector or harness wires, etc were damaged.

Update:
Headlight Switch and Harness Connector Replacement;
"My 1994 F250 had been developing exterior and dash light problems. The symptoms were intermittent dash lights, intermittent radio, trailer brake constantly beeping and both the marker lights and headlights would work, only not at the same time. As all of these symptoms pointed to the common headlight switch, today was the day to find out the cause..." read more by SeattleFSB @ https://www.fullsizebronco.com/foru...-technical-write-ups/343281-headlight-switch-harness-connector-replacement.html

.

 

Aftermarket parts suck! But I swear they don't have any oem parts anymore for these poor things. I would just grab another switch and cross your fingers!

 

After a late night of looking I found the problem. There is more than one hot wire that runs to the switch, one of those wires was dead. When I would jiggle the switch it would completely the circuit giving me both headlights and tail lights. The culprit is a white and tan wire. Once I ran new power no more jiggling the switch

 

Maybe your headlight switch looks like this......

It didnt look that bad from the side you can see

I pulled the switch and connector from a junk yard bronco and replaced the burnt up connectors and have had no issues since.
The junk yard switches are much better (original) quality than replacements.

 

Old thread I know but FYI Rockauto has Motorcraft headlight switches and the connector

 

Had an issue like that on many beaters and as said the switch was the cuplprite. Also ignition column switch has given me intermittent lighting nightmares.

 

yo 445,
Recall, Ignition Switch, Short Circuit Defect info for 88-92 Fords On April 25, 1996 Ford Motor Company announced the recall of approximately nine million cars, trucks and minivans that may be equipped with a faulty ignition switch that may be responsible for causing hundreds of fires. In no case has any death or serious injury resulted from these fires. The recall covers 1988-93 models sold in both the U.S. and Canada that Ford says, "In a very small number of vehilces, the ignition switch could cause an internal short circuit, creating the potential for overheating, smoke and possibly fire in the steering column of the vehicle." The faulty ignitions switches can cause a short circuit that may lead to a fire whether the vehicle is turned on or off."
Source: by AUTOPEDIA™


Same recall except for single year,
Recall, Ignition Switch, Short Circuit Defect info for 90 52539; Recall Summary THE IGNITION SWITCH COULD EXPERIENCE AN INTERNAL SHORT CIRCUIT. Consequence THIS CONDITION COULD CAUSE OVERHEATING, SMOKE, AND POSSIBLY FIRE IN THE STEERING COLUMN AREA OF THE VEHICLE. Remedy DEALERS WILL REPLACE THE IGNITION SWITCH.; miesk5 NOTE; this site will not let you use your browser's Back Button to return to this page; open it a new window
1990 Ford Bronco Recalls, Defects, & Problems

Recalls; check with VIN at dealer or on-line @ Ford;
□
Switch Fires, Part Number SW-2103: "...Over the past two years, this office has experienced fires caused by another potential problem in Ford vehicles. The problem exists within the dimmer portion of the headlight switch in Ford vehicles. The light switch involved is a Model SW-2103. These are the pull out type headlight switches usually located in the lower left corner of the front dash of Ford vehicles. The headlight portion of the switch has two pullout positions, the first for parking lights only, and fully out for headlights and parking lights. The shaft of this pull-out light switch can be turned clockwise and counterclockwise which activates a dimmer switch, lowering and raising the intensity of the lighting in the instrument panels respectively. Fully rotating the shaft counterclockwise past a notch activates the interior lights within the vehicles. The potential problem exists within the dimmer portion of this switch. The dimmer mechanism consists of a metallic resistive coil set inside a ceramic disc positioned over the shaft of the switch. The coil is exposed on its front side away from the passenger compartment. The front side of the coil passes across a contact permitting a current to flow through a certain portion of the coil when the switch is pulled our in its first or second positions. The greater amount of coil through which the current is permitted to pass (clockwise most position) creates the greatest resistance and therefore dims the dash lighting to its lowest intensity. The opposite position provides greatest intensity. Through our investigations, we have found that the coil can fail owing to wear and/or possible material defects or damage. A fractured coil can maneuver itself free of the ceramic disc permitting it to come in contact with the metal bracket which mounts and grounds the switch to the vehicle. When this occurs, a current can flow through a portion of the coil creating high temperatures melting the metal material of the coil and possibly igniting surrounding combustibles. This mechanism has been observed in three separate incidents by this office. Two of these resulted in a fire. The mechanism is precipitated by wear and/or defect in the coil mechanism. If the former is true, we expect there will be an increase in fires caused through this mechanism given an increase in service time. To this date the problem appears to be somewhat limited. However, this particular light switch has been utilized in numerous Ford vehicles. Therefore, a small increase in failure rate owing to age and wear could result in a significant increase in fire losses. The SW-2103 Light Switch Assembly discussed above is reportedly installed in the following Ford vehicles: 1986 -1997 F100, F150, F300; 1990-1994 Explorer; 1987-1994 Ranger; 1987-1990 Bronco II; 1992-1997 Aerostar..." by waltersforensic.com

Miesk5 NOTE: No Bronco Listed, but this may be the result of typos or incomplete research by the company. Also, some small privately owned parts stores may still stock this defective switch. If any unusual exterior or dash light problems occur with symptoms such as intermittent dash lights, intermittent radio, trailer brake constantly beeping and both the marker lights and headlights would work, only not at the same time, pull switch and inspect it, the connector and harness. Reports that new switches are fine, but symptoms occurred because PO or shop removed original defective switch, but connector or harness wires were damaged.

 

My dimmer has been acting up since I bought the bronco, I will need to investigate this sooner than I had planned.....thanks for the info. I need to get a fire extinguisher as well for such possibilities, I really don't want to watch my ride burn to the ground.

 

Can remember having the same issues on my '80 F-250 and first put a new switch...same thing shortly after. Then I found a wire partially burned at the connector. I pulled all the wires out of the light switch block and they didn't seem tight enough...thinking the circuit was broken when the connectors in the plug heated up...so I squeezed all the female connectors a bit, and it was all good after that.

 

Headlight Switch and Harness Connector Replacement