Help troubleshooting automatic door lock issue?

[dwight11]

Hi: I'd appreciate any words of wisdom to diagnose the power locks on my 1998 F-150.

Symptoms:

-The key fob works to lock and unlock both doors (it will make the clicking sound ALWAYS and send current to the actuators; however about 1/4 the time the passenger door doesn't push the lock up fully. In those cases, a few more hits on the key fob will make it unlock).

-The door switches on both doors will always engage the actuators to lock, but neither switch will unlock the doors -- when I push the unlock switch on either door, 99% of the time nothing happens. I have had random success holding the switch on the driver side down for 10-15 seconds and then pushing it down again repeatedly and it will unlock both doors. However, that is not consistent and not reliable.

Questions:

1. Could a weak actuator on the passenger door cause the door switches on both doors to fail only on the unlock selection, even though the key fob always sends current to the actuators?

2. It does seem that I have a weak actuator on my passenger door due to it not pushing up fully much of the time, but does that have anything to do with both my door switches not making any sound or doing anything only on the unlock selection?

3. If one time out of a hundred the door (unlock) switches do engage the actuators and make it unlock, can I rule out the switches being bad?

4. I've seen some forum posts that make me think it might be a bad relay under the dash somewhere. Any thoughts on where it is located on my truck and how can I test it without having a fancy circuit tester?

Any words of wisdom to help pinpoint where the issue may be would be most appreciated.

Thanks much.

 

[Vortigern]

Just a stab in the dark here. I have had that problem with my van. The answer was the door card had been remove and replaced the wrong way. The top part of the card was not first engaged over the rubber groove at the bottom of the window frame where it meets the door card. This was enough to inhibit the free movement of the pin rising when the actuator engaged. Just removed the card and aligned the top of the card properly in the rubber and it worked.

 

[dwight11]

Thanks much for your reply. I don't think that's the problem, however. I already took the door panel (is that what you mean by door card?) off a few days ago and made sure it was put back correctly. Seems to be some sort of electrical gremlins affecting the door unlock switches more than a mechanical constraint. Then again, could be a mechanical constraint. If I'm able to figure it out, I'll let everyone know. Thanks again!

 

[Megawatt]

Hi: I'd appreciate any words of wisdom to diagnose the power locks on my 1998 F-150.

Symptoms:

-The key fob works to lock and unlock both doors (it will make the clicking sound ALWAYS and send current to the actuators; however about 1/4 the time the passenger door doesn't push the lock up fully. In those cases, a few more hits on the key fob will make it unlock).

-The door switches on both doors will always engage the actuators to lock, but neither switch will unlock the doors -- when I push the unlock switch on either door, 99% of the time nothing happens. I have had random success holding the switch on the driver side down for 10-15 seconds and then pushing it down again repeatedly and it will unlock both doors. However, that is not consistent and not reliable.

Questions:

1. Could a weak actuator on the passenger door cause the door switches on both doors to fail only on the unlock selection, even though the key fob always sends current to the actuators?

2. It does seem that I have a weak actuator on my passenger door due to it not pushing up fully much of the time, but does that have anything to do with both my door switches not making any sound or doing anything only on the unlock selection?

3. If one time out of a hundred the door (unlock) switches do engage the actuators and make it unlock, can I rule out the switches being bad?

4. I've seen some forum posts that make me think it might be a bad relay under the dash somewhere. Any thoughts on where it is located on my truck and how can I test it without having a fancy circuit tester?

Any words of wisdom to help pinpoint where the issue may be would be most appreciated.

Thanks much.

Dwight you can buy new fobs and make sure they work at the parts house. Mine completely quit working for a year and for some reason it started working. Go to your parts house and they will fix you up. Get some granite and put some of it in all your locks

 

[SparkyChick]

I've had some similar issues in the past... in one instance it was down to a failing cable in the wiring loom between the door and the main body of the car. In another it was down to minor distortions in the connecting rods inside the door linking the various locking components. Some minor tweaks and a liberal application of some grease sorted that.