Both backup lights on my 87 F150 aren't working. I've replaced them with new bulbs and checked the fuse. Any ideas where else to look?

 

What about the switch that tells the lights when you shift into reverse? I'm not sure exactly where is is located on your truck but that is probably the problem, either that or a bad ground in that circuit.

-Jon

 

Thanks for your suggestion. I'll check my shop manual to see if it's listed. If you can remember the part name, let me know.

 

Thanks again for the suggestion. The part name is the "backup lamp switch" and is located at the rear end of the transmission. It was described and diagramed quite well in my shop manual...

 

Believe it or not, I'm having difficulty finding the part (backup light switch). I've been to several of the local auto parts stores, who said they have the part but when they bring it up, it looks nothing like the part. I've called dealers, who say they can order it, but it's kinda expensive, about $75.00...sheesh.

Anyone know of any websites where I can order a part like this.

 

try these folks:

http://www.forddiscountparts.com/

 

Any ideas where the backup light switch is located? My shop manual doesn't have a diagram for my truck, it's a 1987 F150, 2WD, 6 cyl, 4 sp auto without overdrive.

 

I was looking in my 87 Mitchell Manual for the backup light switch when it dawned on me. If yours was a manual trans, like my 87 Ranger, there is a small 2 wire switch mounted on the left side of the trans.
With an auto trans, the backup switch is actually part of the gear select switch which should be part of the shift linkage that goes into the trans on the left side.
Don't panic about the part I said "part of the shift linkage that goes into the trans'' as you can remove the switch from the outside.
What you can do to test the switch is to disconnect the electrical connector from the switch (should be about 6 wires) and jumper the Purple/Orange with the Black Pink. Turn on the ign switch.
If the backup lights are now on, the switch is out of adjustment or bad.
If it starts ok now, the switch is not out of adjustment, but bad.
(the backup light part)
Remember, the backup lights get power from fuse #5 which also powers up the directional lights. So if they are working, you can check for power at the Gear Select Switch with you test light on the Purple/Orange wire if you want to be sure there is power there.
As I said, if you jumper the two wires and the light comes on, the switch is bad.
Hope this helps.
Mike C.

 

I had a similar problem with my 88 F150 but it was with the taillights/blinkers not working. Replaced both bulbs and checked to make sure the fuse had continuity. After troubleshooting with my DMM, I found faulty wiring. The ground wire was heavily corroded causing the wire to have high resistance. The 12 Volts was present at the plug until the circuit was loaded (brake applied or blinker turned on). I ended up cutting out the ground wires and replacing them.

-Matt