towed boat to ramp for 3rd time this year. turned off lights and parking lights would not turn off. in a hurry for bass tournament so just disconnected both batteries. later reconnected batteries and all ok. turned lights back on then off and parking lights stayed on. after getting home, i could repeat the same situation every time. i then found i could pull fuse 38 for towing and parking lights. (trailer was already unplugged) and lights go out, re-install fuse and no lights on. turn light switch back on and off and parking lights stay on including the warning chime that lights are on. there does not seem to be a relay in this circuit. anyone else experienced this. where can i see a detailed wiring diagram?

 

found some wiring diagrams on the dieselstop forum. not the easiest to follow, but they led me to the 7 way plug for trailer. i unplugged at nearest connector and it did not help which eliminated the plug. however when i plugged back in and pushed wiring back up i heard the chiming stop. looked and sure enough lights were out. turned sw back on and off and lights stayed on. went to same wiring location and carefully tried to narrow down culprit until finally after a few times it quit shorting without me finding problem. will try again when i have help or it screws up, whichever is first

 

Believe it or not need to know ,

Vehicle have single or dual rear wheels
Box or just pick up body, sorry that is just Ford !

 

shortbed single wheels

 

In your owner's manual is a diagram of the CENTRAL JUNCTION BOX.

If you look at the relays in the CJB, there are 3 rows. The middle relay in the center row controls the parking lamps. Remove that relay and the parking lamps should go out. We don't know if the relay is just sticking on or if some other signal is holding it energized. Remove it and install it , let us know what you get, thanks.

 

Hi there, I am having the same issue - even down to the fuse symptons you described. 2002 v10 f250, SRW.
The parking lights stay on once turned on/and then off.

If i pull fuse 38 (trailer tow park lamps and backup lamps) the lights go out. If i put fuse 38 back in, the lights stay off until i turn the lights on. Then, once I turn the lights back off again (with the fuse installed) the lights stay on and the alarm is going off continually.

Were you able to find the issue? Thank you for your help!

 

I tried your suggestion - pulling midde fuse on middle row (fuse 305- trailer tow battery charge relay) and the lights have no change. Any other suggestions?
2002 V10 f250, SRW.

 

From the info have, the following appears to be the path involved.

When the light switch is turned on, that signal goes to the vehicle security module located under the dash, and from there activates a parking light relay which turns the parking lamps on.

Either the relay inside the module is sticking on or something is holding the relay activated,.
pulling the fuse removes the power to the relay but does not activate the relay. That may involve the security module .
There were problems with leaking windshields in those years and models and that affected the CJB (Central Junction Box) and crazy things happened. Further checking will be required to verify if this could be causing the problem.

 

Thank you for your reply.
From what im hearing and seeing this has to be a damaged relay some where....Would you be able to point me in the direction of further relays to be found?
Ive pulled every relay I can find and even switched relays out with like kind relays to see if that would fix the issue - there as been no change. Lights stay on.
Thank you!

 

I'm afraid this is a little more complicated than just replacing something like a relay.

The relay is the result , but in this case I do not believe to be the cause.

Something is activating the relay or holding it activated and that is what we need to determine before any corrective action can be taken.