1996 Cherokee - Power Door Locks

#1

I have a problem with unlocking doors with the power door locks(PDLs). The PDLs switches, located on both the driver and front passenger doors, work just fine to lock all 4 doors and rear hatch of the vehicle. However, they do not unlock any of the doors. When unlocking with the PDLs I can see the door locks at the door latch handles move from the lock position to the toward the unlock position but they do not fully get to the unlock position. One must reach over and manually push the locks fully to the unlock position.



I am hoping since all 4 doors (and the hatch) all mis-operate the same way that one single component in the system is failing rather than all five individual locks(doors and rear hatch).



thanks in advance, Mike S

#2

This MAY be a wiring fault or perhaps just a dry mechanism in the doors due to age and possible moisture accumulation. (Although UNLESS this has been gradual, it may not be the problem)

Does this happen while the engine is running and charging the battery, or just when the engine is NOT running and the battery is the sole power supplier?
How old is this battery?

You’ll have to test the power going to one of the power door lock actuators.

This means removing one door panel to gain access.

Check to make certain you have full voltage going to the drivers arm rest power door lock switch from the fuse panel.

#3

Thanks for the follow up Roadrunner.

I have already tried to lubricate the door lock switches on two doors to no avail. I simply removed the small cover at the door handle not the entire door panel. Maybe there is more that could be lubricated.

The issue occurs whether the car is running or not running and is the same with both the drivers PDL and the front passenger PDL. I am not sure of the age of the battery.

I will check the voltage at the PDLs and at each door actuator.

Thanks, Mike S

#4

Mike, the vehicle isn’t REAL old (12 yrs), but although each door has a plastic moisture barrier, (be careful not to rip it) there is a possibility the electrical connections may be corroded.

Just something else to inspect while it’s all opened up.

#5

This problem screams “look at the schematic” See if there is a module involved.

#6

The only module connected to this system here is the BCM.

The system is fully controlled by the BCM, diagnosis is limited to simple checks of the wiring connections, switches and actuators for minor faults that can be easily repaired.

PROIVIDING, the Cherokee system is the same as GM vans.

#7

I still say look at the schematic,maybe it’s like GM maybe not,up to you if you want to verify the type of system you are working on.

As Roadrunner says,it’s all simple and easy.