Power locks not working

rammertide07 · #1 Sun, February 26th, 2012, 03:39 PM

My power locks have not worked in the 3 yrs that I have owned the truck. The key fob and communication works. The fob nor the door switches will work the locks. I pulled fuse 26 I'm the power distribution box to check it and the truck turned off. Put the fuse back and I was able to start the truck. One of the legs of the fuse looked burned but the element seemed to be intact. I believe I replaced the fuse a couple of yrs ago and the looks seemed like they didn't have enough umph to actuate. Every time i tried to work them it seemed like they were getting less and less juice each time.

When I talked to Bill, he told me Cost was the expert on this issue.

cj45lc · #2 Sun, February 26th, 2012, 05:46 PM

Mine got to where they would work but were real weak & then it got to the point that you could hear them trying to work but just wouldn't get it done. I went ahead & got the new lock actuaters from Ford for about $35 a piece & everything has been fine. There is a write up about taken the thing apart & wrapping tin-foil around some part of it to make them work but I was told the newer actuaters were the way to go. It's one of them jobs that took me close to an hour to do the 1st one & maybe 20 mins to do the other. It was worth it to me to buy the new ones & be done with it

***cleatus12r*** · #3 Sun, February 26th, 2012, 09:33 PM

The door lock actuators use a thermal resistor circuit breaker. It's a safety feature to keep kids/dogs/cargo from burning the truck to the ground if the door lock switch is depressed too long. As the temperature of the circuit breaker goes up, so does the resistance. As resistance goes up, the current though the circuit goes down thus minimizing heat created in the circuit in the event of a short or a switch depressed for an excessive amount of time.

Over time, these resistive circuit breakers "wear out" electrically and limit current to the actuator motor windings even under normal (cool) situations. Yes, it is possible to disassemble the actuators and provide a parallel shunt across the circuit breaker but it's not adviseable due to safety reasons.

Unfortunately the only way I know of doing it properly is to replace the entire actuator in each door (which if you have a crewcab truck will cost you plenty).

rammertide07 · #4 Sun, February 26th, 2012, 11:19 PM

Quote:

Originally Posted by cleatus12r

The door lock actuators use a thermal resistor circuit breaker. It's a safety feature to keep kids/dogs/cargo from burning the truck to the ground if the door lock switch is depressed too long. As the temperature of the circuit breaker goes up, so does the resistance. As resistance goes up, the current though the circuit goes down thus minimizing heat created in the circuit in the event of a short or a switch depressed for an excessive amount of time.

Over time, these resistive circuit breakers "wear out" electrically and limit current to the actuator motor windings even under normal (cool) situations. Yes, it is possible to disassemble the actuators and provide a parallel shunt across the circuit breaker but it's not adviseable due to safety reasons.

Unfortunately the only way I know of doing it properly is to replace the entire actuator in each door (which if you have a crewcab truck will cost you plenty).

Thanks for the reply Cody. Is this something that would happen to all 4 doors at once? After I replaced the fuse, I was able to get the locks to attempt to actuate. But they all seemed like they wasn't getting enough juice, and each click of the button the juice seemed to decrease a little bit at a time...to all of the door locks.

I'm going to attempt to install a security system and it would be nice to have the door locks operating. Otherwise I wouldn't be worrying about it.

rammertide07 · #5 Sun, February 26th, 2012, 11:20 PM

Is there a wire I can check to see if it gets voltage when the lock/unlock button is pressed?

***cleatus12r*** · #6 Mon, February 27th, 2012, 12:05 AM

The switches control the ground circuit of the lock actuator motors. The common scenario is that the actuators get weaker after the first button press and then begin to do less on subsequent presses.....once you let them rest for a few minutes, you can repeat the process.

It's not hard to test, but the best way to do it is to actually measure current flow through the circuit. Measuring voltage will only test the switches, power, and ground circuits.

It's not uncommon for all of the actuators to take a dump (my 01 CC was the same way). One fails and the others slowly follow until none of them work.

rammertide07 · #7 Mon, February 27th, 2012, 12:39 PM

Okay, I'll probably get 2 actuators and see if that does the trick. If so, I'll buy the other 2. Thanks for the info Cody.

rammertide07 · #8 Mon, February 27th, 2012, 12:46 PM

Amazon has them pretty cheap...

Amazon.com: Dorman 746-149 Door Lock Actuator: Automotive

They also have EBP sensor for $76. Gotta get one of those too and tube.

winniety · #9 Mon, February 27th, 2012, 11:16 PM

the simply way is change a new power lock
safy and fast
this situation is annoying

Lowdown89 · #10 Sat, March 3rd, 2012, 11:44 AM

You can also pull the actuators and drill out the rivets and replace the little piece tht wears out with a piece of thin copper or something of the sort... That's what I did and my door locks one work like new now I'm sure if you hold the locks down something is gonna get hot and I voided some kinda safety feature but it was free and took about 2 hours start to finish