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Discussion Starter #1
Hey guys, I've got an '89 SC and the headlights will flicker on and off from time to time. Usually it happens when running the factory fog lamps, but sometimes while using just the headlights ( on low or high beam ) for a while and hit a bump in the road. I did pull the light switch out thinking it was a loose wire issue and fount the plastic terminal to the harness that plugs into the light switch was distorted / partially melted ( not as bad as it sounds ) and the main power wire was loose.
Went and got a new terminal and got it all wired in and the problem has improved some, the heads lights still will go out and come back on after being on for awhile and hitting little bumps in the road.

So now I'm kinda lost as to where to look now. I'm thinking it's either the switch itself or possibly the multi-function switch. The differrence it $30 for a new headlight switch and $190 for the multi-function switch. Anyone have to deal with this problem before? Is it more than likely one of these switches or something else entirely? Anyone know of any tests that can be done to check them to determine which one is the culprit? Any help is appreciated.
 

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Hey guys, I've got an '89 SC and the headlights will flicker on and off from time to time. Usually it happens when running the factory fog lamps, but sometimes while using just the headlights ( on low or high beam ) for a while and hit a bump in the road. I did pull the light switch out thinking it was a loose wire issue and fount the plastic terminal to the harness that plugs into the light switch was distorted / partially melted ( not as bad as it sounds ) and the main power wire was loose.
Went and got a new terminal and got it all wired in and the problem has improved some, the heads lights still will go out and come back on after being on for awhile and hitting little bumps in the road.

So now I'm kinda lost as to where to look now. I'm thinking it's either the switch itself or possibly the multi-function switch. The differrence it $30 for a new headlight switch and $190 for the multi-function switch. Anyone have to deal with this problem before? Is it more than likely one of these switches or something else entirely? Anyone know of any tests that can be done to check them to determine which one is the culprit? Any help is appreciated.
The MF switch on the column. has NOTHING to do with your headlight issue, especially if the issue is only with lowbeams.

Fords from that era had headlight switch issues. Just replace the dash headlight switch and go from there. We are talking about a 20yo part that sees very high current. A likely failure point.
 

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Discussion Starter #3
Well, my brother had a '90 Bird LX with fog lights and his car was doing the same thing and his problem was the MF switch. My problem has improved after replacing the harness, but still goes off and on, just not as often....and when it does now, it's mostly after using the high beams and/or for lights...it's only done it once on low beams and that was after the lights went off and back on when I had the fog lights on.
 

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Well, my brother had a '90 Bird LX with fog lights and his car was doing the same thing and his problem was the MF switch. My problem has improved after replacing the harness, but still goes off and on, just not as often....and when it does now, it's mostly after using the high beams and/or for lights...it's only done it once on low beams and that was after the lights went off and back on when I had the fog lights on.
Looking at the wiring diagram now it could be. Is there any way you can disassemble the switch and possibly clean it out? I've done that on other Fords. It is an outrageously expensive part.
 

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The early headlight switches, as mentioned above, Are prone to failure in this fashion.. There is an upgraded Headlight switch, which you more then likely will not get through a place like Napa, ect, since the companies they use for the parts most likely used the Original as a template on making the replacment part..
I do not remember the Ford replacement Part number thou...

Usually if the problem Continues after you've replaced the headlight switch, it's because their is too much load on the headlight switch itself, which can cause the plug or Harness to have melt at the Headlight switch itself, or even at multifunction switch.. (all of which happened to me in my '91 XR7)

Also the best cure is to just add relays to the headlights and Fog lights (if so equipped) AFTER fixing any issues there may be with at the headlight and Multifunction switch :)
 

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Discussion Starter #6
I dont't know If I can clean it up any or not tbirdguy, I haven't pulled it out yet. Probably will in the next couple of days. The MF switch is $190.00 so I really hope that aint it. My brother only paid $75 for his 4 years ago...$190 is just plain crazy for that part.

91 XR7: I'll keep that in mind. Question though, do you add the relays behind the switch or just before the each headlight and each fog light (equipped) and which relays do you use?? I'm not up to par on chassis wireing....just stereo wireing, the chassis stuff confuses me.
 

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Usually you can pick up a harness that plugs into the Factory Headlight plug, and then you connect it to the headlight bulbs and two other wires to the battery (Ground and Positive)

I myself made up my own harness, and such.. since it was cheaper and i like doing my own thing :)
 
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