93 Cherokee Power Door Lock Problem
 

Last week my power door locks decided to stop working. All of them at the
same time. When you press the switch on the front doors you can hear
clicking under the dash. It looks like there are three relay switches under
the dash that are making the clicking noise. Anyone have a solution? Very
frustrating.

Re: 93 Cherokee Power Door Lock Problem
 

Al --

Here are some answers I got a similar problem some time ago; usually in my
case, however, one or other of the rear doors doesn't unlock. I got some
silicone lube spray, but still haven't got around to taking the door to
pieces! Hope you find these of some help, anyway.

The drivers and passenger door locks also have a switch in them. It's likely
to be one of those motors.

The pulse from alarm tells it to unlock, but because it didn't manage to
open all the way, the switch immediately tells the doors to lock again.

I would start by seeing if the doors unlock with the key from the passenger
door as it does the drivers. This might help indicate if the drivers door is
at fault.

When you turn the key in the drivers door, you are physically lifting the
drivers motor, so if that was the weak one, you have just manually overidden
it!

The next thing would be to disconnect the wires to the drivers doorlock
motor if thats the type of task you would take on?

Then try your remote again (with the door closed) and check its behaviour.
If it works all the other doors then that was the problem. It could equally
be the passeneger door causing the problem however.

My thoughts are that the alarm system is certainly not at fault. The CDL
unit is probably OK. They tend to work or fail completely. That just leaves
the door locks or a wiring fault (short circuit).

Good luck.

****************

Probability is that the lubricant/grease on the locking mechanisms
inside the door has hardened/polymerized and you need to relubricate the
internal arms, joint and electric operator inside the doors.

Next time this malfunction is noted, look to see which door doesn't
open/close by noting the individual mechanical lock switches (fob?) at
the inside door release handle .... or try each door until you find the
one that doesn't operate.

Then disassemble the door by removing the interior armrest, vinyl/fabric
panel (pry from the bottom of the inside panel to disengage the plastic
retainers), etc. By hand - operate the arms etc. inside the door while
spraying a Teflon or Silicone lubricant until the offending joint
loosens. The electric 12v operator is located down inside and to the
front. You will have to remove a small rubber bellows/boot to lubricate
the operator.

Hope you have small hands or you will inevitably scrape and cut yourself
on the sheet metal edges, etc.

;-)


If some doors unlock, and some don't, then I would suspect
mechanical, like needing lube (thanks RichH).

Since they *all* don't unlock, every time it fails, I'd suspect electrical.
There should be relays for both lock and unlock... make sure that
these relays are closing (do you hear a click when you ask for
unlock, even when it fails to do so?) so you know that the wiring *to*
the relay is good. Now swap the relays... does the problem go
with the relay, or stay where it was? If it goes, it's a relay.
If it stays, it's wiring/connections. Basic troubleshooting 101.

Re: 93 Cherokee Power Door Lock Problem
 

Al --

Here are some answers I got a similar problem some time ago; usually in my
case, however, one or other of the rear doors doesn't unlock. I got some
silicone lube spray, but still haven't got around to taking the door to
pieces! Hope you find these of some help, anyway.

The drivers and passenger door locks also have a switch in them. It's likely
to be one of those motors.

The pulse from alarm tells it to unlock, but because it didn't manage to
open all the way, the switch immediately tells the doors to lock again.

I would start by seeing if the doors unlock with the key from the passenger
door as it does the drivers. This might help indicate if the drivers door is
at fault.

When you turn the key in the drivers door, you are physically lifting the
drivers motor, so if that was the weak one, you have just manually overidden
it!

The next thing would be to disconnect the wires to the drivers doorlock
motor if thats the type of task you would take on?

Then try your remote again (with the door closed) and check its behaviour.
If it works all the other doors then that was the problem. It could equally
be the passeneger door causing the problem however.

My thoughts are that the alarm system is certainly not at fault. The CDL
unit is probably OK. They tend to work or fail completely. That just leaves
the door locks or a wiring fault (short circuit).

Good luck.

****************

Probability is that the lubricant/grease on the locking mechanisms
inside the door has hardened/polymerized and you need to relubricate the
internal arms, joint and electric operator inside the doors.

Next time this malfunction is noted, look to see which door doesn't
open/close by noting the individual mechanical lock switches (fob?) at
the inside door release handle .... or try each door until you find the
one that doesn't operate.

Then disassemble the door by removing the interior armrest, vinyl/fabric
panel (pry from the bottom of the inside panel to disengage the plastic
retainers), etc. By hand - operate the arms etc. inside the door while
spraying a Teflon or Silicone lubricant until the offending joint
loosens. The electric 12v operator is located down inside and to the
front. You will have to remove a small rubber bellows/boot to lubricate
the operator.

Hope you have small hands or you will inevitably scrape and cut yourself
on the sheet metal edges, etc.

;-)


If some doors unlock, and some don't, then I would suspect
mechanical, like needing lube (thanks RichH).

Since they *all* don't unlock, every time it fails, I'd suspect electrical.
There should be relays for both lock and unlock... make sure that
these relays are closing (do you hear a click when you ask for
unlock, even when it fails to do so?) so you know that the wiring *to*
the relay is good. Now swap the relays... does the problem go
with the relay, or stay where it was? If it goes, it's a relay.
If it stays, it's wiring/connections. Basic troubleshooting 101.

Re: 93 Cherokee Power Door Lock Problem
 

Al --

Here are some answers I got a similar problem some time ago; usually in my
case, however, one or other of the rear doors doesn't unlock. I got some
silicone lube spray, but still haven't got around to taking the door to
pieces! Hope you find these of some help, anyway.

The drivers and passenger door locks also have a switch in them. It's likely
to be one of those motors.

The pulse from alarm tells it to unlock, but because it didn't manage to
open all the way, the switch immediately tells the doors to lock again.

I would start by seeing if the doors unlock with the key from the passenger
door as it does the drivers. This might help indicate if the drivers door is
at fault.

When you turn the key in the drivers door, you are physically lifting the
drivers motor, so if that was the weak one, you have just manually overidden
it!

The next thing would be to disconnect the wires to the drivers doorlock
motor if thats the type of task you would take on?

Then try your remote again (with the door closed) and check its behaviour.
If it works all the other doors then that was the problem. It could equally
be the passeneger door causing the problem however.

My thoughts are that the alarm system is certainly not at fault. The CDL
unit is probably OK. They tend to work or fail completely. That just leaves
the door locks or a wiring fault (short circuit).

Good luck.

****************

Probability is that the lubricant/grease on the locking mechanisms
inside the door has hardened/polymerized and you need to relubricate the
internal arms, joint and electric operator inside the doors.

Next time this malfunction is noted, look to see which door doesn't
open/close by noting the individual mechanical lock switches (fob?) at
the inside door release handle .... or try each door until you find the
one that doesn't operate.

Then disassemble the door by removing the interior armrest, vinyl/fabric
panel (pry from the bottom of the inside panel to disengage the plastic
retainers), etc. By hand - operate the arms etc. inside the door while
spraying a Teflon or Silicone lubricant until the offending joint
loosens. The electric 12v operator is located down inside and to the
front. You will have to remove a small rubber bellows/boot to lubricate
the operator.

Hope you have small hands or you will inevitably scrape and cut yourself
on the sheet metal edges, etc.

;-)


If some doors unlock, and some don't, then I would suspect
mechanical, like needing lube (thanks RichH).

Since they *all* don't unlock, every time it fails, I'd suspect electrical.
There should be relays for both lock and unlock... make sure that
these relays are closing (do you hear a click when you ask for
unlock, even when it fails to do so?) so you know that the wiring *to*
the relay is good. Now swap the relays... does the problem go
with the relay, or stay where it was? If it goes, it's a relay.
If it stays, it's wiring/connections. Basic troubleshooting 101.

Re: 93 Cherokee Power Door Lock Problem
 

Al --

Here are some answers I got a similar problem some time ago; usually in my
case, however, one or other of the rear doors doesn't unlock. I got some
silicone lube spray, but still haven't got around to taking the door to
pieces! Hope you find these of some help, anyway.

The drivers and passenger door locks also have a switch in them. It's likely
to be one of those motors.

The pulse from alarm tells it to unlock, but because it didn't manage to
open all the way, the switch immediately tells the doors to lock again.

I would start by seeing if the doors unlock with the key from the passenger
door as it does the drivers. This might help indicate if the drivers door is
at fault.

When you turn the key in the drivers door, you are physically lifting the
drivers motor, so if that was the weak one, you have just manually overidden
it!

The next thing would be to disconnect the wires to the drivers doorlock
motor if thats the type of task you would take on?

Then try your remote again (with the door closed) and check its behaviour.
If it works all the other doors then that was the problem. It could equally
be the passeneger door causing the problem however.

My thoughts are that the alarm system is certainly not at fault. The CDL
unit is probably OK. They tend to work or fail completely. That just leaves
the door locks or a wiring fault (short circuit).

Good luck.

****************

Probability is that the lubricant/grease on the locking mechanisms
inside the door has hardened/polymerized and you need to relubricate the
internal arms, joint and electric operator inside the doors.

Next time this malfunction is noted, look to see which door doesn't
open/close by noting the individual mechanical lock switches (fob?) at
the inside door release handle .... or try each door until you find the
one that doesn't operate.

Then disassemble the door by removing the interior armrest, vinyl/fabric
panel (pry from the bottom of the inside panel to disengage the plastic
retainers), etc. By hand - operate the arms etc. inside the door while
spraying a Teflon or Silicone lubricant until the offending joint
loosens. The electric 12v operator is located down inside and to the
front. You will have to remove a small rubber bellows/boot to lubricate
the operator.

Hope you have small hands or you will inevitably scrape and cut yourself
on the sheet metal edges, etc.

;-)


If some doors unlock, and some don't, then I would suspect
mechanical, like needing lube (thanks RichH).

Since they *all* don't unlock, every time it fails, I'd suspect electrical.
There should be relays for both lock and unlock... make sure that
these relays are closing (do you hear a click when you ask for
unlock, even when it fails to do so?) so you know that the wiring *to*
the relay is good. Now swap the relays... does the problem go
with the relay, or stay where it was? If it goes, it's a relay.
If it stays, it's wiring/connections. Basic troubleshooting 101.