My 1995 F150 4x4 has no backup lights. My research leads me to believe the backup light switch failed. Here's the kicker: I can only find backup light switches for manual transmissions. This makes me think I'm doing something wrong. Who's gonna be the first person to set me straight?
The switch will be part of the range sensor.
99% of pickup truck rear light issues are the harness back by the rear bumper, though.
In reply to Streetwiseguy :
Range sensor?
In reply to thatsnowinnebago (Forum Supporter) :
It should be a sensor mounted to the shaft of the gear selector lever on the transmission, from what I remember of it. Is yours an E4OD, AOD, or something else?
I'd first test the wiring harness at the junction back at the bumper though
In reply to Mr_Asa :
It's the 4R70W. Which I guess is some variation of the AOD trans?
I'll poke around at the back of the truck tomorrow after work. My battery also E36 M3 the bed on the way home tonight so I may have to get clever with the testing.
4r70w is indeed an evolution of the AOD.
Depending on the parts catalog, it might be called the NSS, range switch, or shift selector switch. It slips over the shift shaft that goes into the transmission case on the driver's side and it's just a switch that moves with the shaft to tell the computer what position the switch is in. It uses that to know what to tell the internal solenoids to do, prevents the starter from engaging while in anything but P or N, and activates the backup lights when in R.
A switch going bad is not uncommon and it's a pretty easy fix. They are shipped in the neutral position, so you put the truck in neutral, crawl under, replace the switch, and it should be adjusted properly.
The switch fits pretty tightly over that shaft and you'll find crusty dirt and rust on the shaft. You will most likely destroy the old switch getting it off, but then use plenty of wire wheels, sandpaper, files to clean up the shaft, otherwise you risk destroying the new switch getting it on. I found that a properly-sized deep well socket helps to tap it on. Just make sure you're tapping on the little ring that fits over the shaft instead of the body of the switch.
Make sure you have it fully bottomed on the shaft. You'll know it's right because the holes will sit flush on the bolt bosses. Don't try to draw it in with the bolts or you'll just deform the switch and cause binding in the guts.
That's not a diagnosis, just info in case you need to get one. Test light first. IIRC, the NSS on a 4R70W sends 12v+ to the lights as opposed to grounding the light circuit, but googly some wiring diagrams.
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