kgrun4

So I the other day I noticed that my reverse lights are always on when I turn my lights on. Technically only my left on is always on, right one is out, I need to check if its completely out even when backing up. Funny thing is this relieved some issues I thought I was having with my new aftermarket stereo because I at certain times I couldnt' use the touchscreen at all, now I realized its because when my lights are on and the reverse lights are on the radio thinks I'm in reverse as well!

Any ways, I've used the search on here and found other people had problems with this but it seems there's were on all the time, where as mine are only on when I turn my lights on.I don't think its a case of the switch being stuck on because I should have the reverse lights on all the time then, which I don't. People pointed to the SJB being bad, possibly because of the dreaded water leak. I haven't noticed any water soaked carpet or anything yet. I've only been driving my car for about a month and when it was being repaired by my dad and uncle's shop, my uncle looked at the TSB for the water leak and did the things that were suggested to prevent the leak from happening. Doesn't mean it didn't get the leak before I owned it but it hasn't happened since I had it.

So I figured I'd post here and see what people thought before my takes into his shop and takes a look at it. Its an 05 V6 auto if that helps any.

kgrun4

bump for some morning views

SilvaDragon

If you hadn't said anything about the stereo lockout, I would have suggested
a floating ground in the taillight wiring. Those types of problems can be hard
to find, but easy to fix if you do find it.

But if the stereo locks out with the lights on, then the problem has something
to do with detecting reverse, and that opens a much bigger can of worms,
involving the SJB, PCM, and more.

Anyway, you could go ahead and pull Fuse #62, which supplies power to
the backup lights, then turn on your headlights and see what happens.
If the backup light comes on, then we're back to the floating ground.
If not, well, you'll need to check for codes and walk the diagnostic procedure.

GrayPony

Smart junction box corroded in the pass kick panel?

Nuke

I like the fuse pull for starters, AFTER you also confirm if the other side has a blown bulb or the fault is only allowing one side to light. That will be helpful for any additional troubleshooting.

kgrun4

Thanks for the advice so far...might be able to check this stuff out more friday night, if not then the weekend. I pulled the fuse and problem still exists, but then I looked and saw Nuke suggested to do that after checking the other bulb, which I haven't done yet. I'll re-do the fuse pulling soon after figuring out the right side bulb situation.

I did check the SJB area, pulling out the kick panel cover. It wasn't wet but under the carpet you could see where there was dirt so its possible it had been wet around there before.

Nuke

You can find the wiring diagrams here: http://iihs.net/fsm/?dir=1

You may have to begin pulling fuses 0ne-by-one until you find the guilty circuit that's powering up those lights, then go from there using the diagrams.

157dB

Maybe start at the reverse light switch on the tranny and
ohm it out to confirm proper operation first? Just by pulling
the connector off the reverse light switch on the tranny
and the reverse lights going out would rule out a bad SJB.

The Ford diagnostic procedures are HERE.
Do it just like Ford would do.
Become the service technician...

Nuke

Does that mean he'll have to get retarded drunk, hit himself in the head with a hammer and shove a grenade up his butt to begin?

SilvaDragon

So that's what I would have suggested before looking at the wiring diagrams.
Looks like Ford has a digital selector in the gear shift, and that talks back
to the SJB, and when the SJB thinks you're in reverse, it triggers a reverse
relay, which sends a signal to the PCM to put the trans in reverse, and then
triggers the reverse lights to come on. So, it's not going to be that easy
to find if it's not a basic wiring problem in the trunk. But since the trans
doesn't go into reverse when the lights come on, there's hope.