1999 Explorer Power door locks go crazy after hitting the Fob or pressing the button.

[BillRod]

1999 Explorer Power Door Locks go crazy after hitting the Key Fob or pressing the button.

This happened when I first bought it about 4 years ago.
I replaced both Door Lock Relays and that took care of it until now.
Same Issue now but replacing both relays has no affect.
I also tried different combinations of the 4 relays using the new and old with no change.

What else should I look at?

Thanks in advance
Bill

 

[RonD]

If its like a Ranger of the same year, which is likely, then door lock relays are activated by Grounding

The relays all have 12volts all the time, not just key on power

The door switches ground a relay to either lock or unlock

Same for RAP module(fob interface), it grounds a relay to lock or unlock

A switch may be failing so is a partial ground but not quite enough to activate the relay until its grounded by fob or switch

I would unplug door switches, one at a time, and see if problem goes away, also jiggle the wire to see if there may be a short where it goes thru door jamb and into the cab

If not then it could be the RAP module