hi,
just got a 1999 F150 and the door locks only work with a key.
both switches do nothing like no power, fuse has power but the switches do nothing, no noise no click nothing on both driver and passenger side,
also the alarm seems to be not working but the fuse has power and not blown.
the blue light does not come on.
what would make both door locks not work with switch and the alarm not work?
i just got the truck so do not know history..
can anyone help?
i hate taking to a dealer unless i have an idea what is wrong and what the cost will be.

thanks

 

https://www.f150online.com/forums/el...locks-too.html

Look at this post. SSCULLY (A very smart guy) gave me some good sustem diagrams for the door locks.

My issue was a weak battery. But a few days later showed up in a bad driver side switch. If you search power window switch repair it is very simular.

Good luck.

 

I had the same problem and I had to replace both actuator for the locks and they work now

 

have the same problem with my '99, except the locks will click just sounds real weak and will not move door locks

 

The fail regular. Not all that easy to replace either.

 

Mines been that way for years now, someday I'll get it fixed but it's not high on my to do list.

 

Yea, mine aren't working now. I'll take them apart at some point. I believe something corrodes somewhere inside. Cleaning may solve the prob.

 

Disable the alarm and try the door locks.

 

My driver side was not working either when I bought it. The issue was that I heard grinding so the switch was working.

There is a DC brushed motor that has gears attached to the motor shaft...that move a long piece plastic with gears that is attached to the lock mechanism via a long rod....gears (plastics) had worn out on mine.

My solution was to just add a metal wedge in there as to make the worn gears make better contact...been working ever since I bought the truck..since I registered here.

I also fixed my brothers on his truck...his the problem was the DC brushes where gone...needed a new motor or the whole thing new...i just replaced the brushes.