2004 Super Crew Lariat 4WD

for several month the passenger side lock hasnt worked electrically at all, not with the fob or with either switch. The other 3 locks work normal. Before it quit working it would work sporadically, then just stopped all together.

last night I decided to figure out the problem, figured the actuator was bad and decided to take it apart to see if I could see the problem. Took it apart, nothing obvious... put it back together, hooked 12v to it and it works flawlessly in both direction with an outside power source.

cleaned both switches and made sure all connection (in the door) were tight.

any ideas where to go next?

 

Use your meter and make sure you're getting power from the source....if no power star to look for a bad wire or loose ground......

 

the weird thing is when I put the tester on the plug going to the actuator and push the button the tester lights up momentarily on the up side only....I am assuming I would need to hook the tester to power to make it light up when I push the button on the down side?

Is it possible that the actuator will work well enough to move the arm on the motor itself but not have enough power to move the entire lock rod?

 

http://www.ford-trucks.com/forums/44...cks-fixed.html

http://www.ford-trucks.com/forums/95...-pictures.html

It seems in a lot of lock actuator issues the thermal resistor in the motor might be the issue....

 

also check the rubber door boot between the truck body and door...pull the boot back and make sure that none of the wires are pinched or broken.

 

Originally I assumed it was fine....however I just realized when I was testing the connection I had my test light grounded to a door hinge bolt. I noticed 2 black wires in there, I assume both are grounds?

 

as far as oem wiring goes, black doesnt always mean ground.....usually it is but not always. best way to test is with a digital multi meter. that way you can test for ground continuity. id pick a more solid ground point just so youre sure you have a good solid ground for your light.