Hey guys!
I have a 2008 F150 in the shop and im having an issue figuring out a problem with reverse lights.

The truck came in with reverse lights that would not turn off. It did not matter what gear, if the key was on or off.
The are on full bright, I pulled both fuses for the reverse lights (trailer relay and regular lights.)
I also unplugged the connector from the transmission.

Customer also complained that the ABS light came on at the same time.

I checked the wiring diagram on alldatapro, and I cant seem to find the connection.

then they went out after the truck sat in the shop for a while. no abs light, no reverse lights.

I tested reverse and the lights came on. Road tested and everything was fine.

An hour later I started the truck and the ABS light came back on and the reverse lights came back on and wouldnt go out.

Its getting annoying, I have traced the wires and cant find anything.

what gives? any of you had this ussue?

Thank you

-Steve

 

I seen a super duty that this happened to and they found it was the alternator and a charging malfunction. May be somthing worth a look or yours could be totally different

 

have you checked the reverse light switch? faulty switch maybe?

 

I unplugged the light switch and they stay on. Power is somehow getting to the backup light wire, not on the trailer wire side, as its relay'd.

Im getting pissed off at it, lol

I have checked everything I can think of

 

Have you checked for a short in your reverse light wiring?

 

well wtf lol. its getting power from somehweres

 

did you try to trailer relay? could the relay be messed up? i just pulled up the diagram for the reverse lights on mitchell and i dont see anything that could be keeping it on other than that. the reverse lights are their own circuit.

 

I pulled fuse that controls backup relay. seemed to fix it for a bit then the problem came back. I cant find a short anywhere. must be a hard short as the lights are full bright.
Im getting pissed off lol

 

damn, i was hoping that was it. thats going to be a tricky one man.

 

you said you already pulled fuse 14 and the reverse light switch?