1nutinthewater

The power door locks on both drivers and driver side rear do not work with the remote or the button- only by manual lock.
Any ideas on what to check?

wingless

Welcome to the forum.

The most common problem is broken wires in the door jamb boot, as shown in this reply.

1nutinthewater

Excellent thank you!!

1nutinthewater

Well the wires are all fine- Any clues as what to check next? Drives me nuts all the doors do not lock/unlock together.

wingless

The lock motors either get a voltage pulse when the lock switch is activated or not.

A DC voltage meter monitoring the voltage at the motor will show if the required voltage pulse exists.

If no voltage pulse, then trace the problem using the wiring diagram.

If yes voltage pulse, then the lock motor is bad.

er mac

I had an issue today we're only my driver's door would lock or unlock. Ended up being the solder joints on the power lock switch on the passenger side

1nutinthewater

Now its the 3 doors- Only the passenger rear locks................

Rapidrob

I just repaired three door locks on my '98 ZJ.
You do not mention if you hear any sound coming from your three locks? If you hear a buzzing sound for more than one second the lock is broken internally.
with the weather getting cold,this would make sense.
If you hear no sound from the lock(s), your not getting power to them. As stated above the wiring is the issue. ( all remote locks are controlled from the electronics box in the front passenger door. There are solder joints that can crack and prevent normal operation) I would check here if you hear no sound when locked/unlocked from the remote.
If you do hear a buzzing, the clutch in the lock ( blue plastic) is broken in half. Very cheap plastic that gets hard with age. The motors I found out,are very well made and drive several gears to increase the torque to move the door locks when cold or hot.
I went the the wrecking yard and had to pull nine locks to find three that worked ( portable pocket power supply I made). The plastic clutch had failed in every lock that did not work. All motors worked just fine.
I brought home the three working locks and tore them apart. All of the lithium grease had gotten hard and was so contaminated with crud from all these years that the gears bound up causing the clutch to break in half allowing all of the gears to freely spin under no load causing the buzzing sound of the drive motor.
When working, the gears and levers inside of the lock barely move 1/4-3/8 of an inch. But the torque is very impressive.
You cannot buy this clutch,you have to replace the whole lock assembly. A very poor design that is prone to failure.
I have done a very long winded post on another site on how to clean you door locks to prevent this blue plastic clutch from failing costing you big bucks for a replacement lock assembly.


The screw driver is pointing to the whole clutch assembly. You can just see the blue plastic directional clutch that throws the "D" shaped cam into locking ***** that cause the main driven gear to move a dog-leg gear and lock / unlock the door. IF we could get the blue plastic clutch,we could fix the locks for a few pennies.

There is the part that fails. All it does is move the "D" shaped cam and allows the cam to bind and engage the dog leg gear ( not shown)
I have a full photo essay on tearing the lock apart and cleaning / lubing it again. My locks now work like new and barley make a sound when locking/unlocking.