Power window replacement

[coman]

The drivers side power window needs replacement.  I have ordered 2 parts (1 from dorman and 1 from salvage).  Neither fits.  The car part listing says that Cherokee is compatible but its not.  Is the common model the Wagoneer in 1987?  The assembly on the bottom is what I removed.  The other one is the Dorman part. 

[Minuit]

Cherokee power window regulators should fit in an MJ's door no problem.

 

Can you describe the problem with fitment? Also, what's wrong with the regulator you took out? If it was just slow, they can be cleaned easily.

[coman]

Snake frame is different.  Mounting flange on motor and other hole patterns are wrong.  Electrical connector is wrong.

 

[coman]

The snake is damaged.  Window will rise to a certain point then stop.  Motor continues to run.  Some splines on the snake are missing.

[coman]

I am reading your Comanche build log.  Nice work.  Detail is supreme.  I just got to the place where you mention the window.  If I could find a snake replacement I might be happy.

 

[coman]

The motor works and surely needs cleaning.  Can you note a reference in your log that I can follow?

 

[Minuit]

That looks... vaguely like an XJ power window reg, but none that I've seen have ever looked like that. Every one of them I've personally taken out of an XJ (or MJ) have looked just like your original. Older ones were held in with rivets and newer ones are held in with bolts, but still the same shape. I wonder if that's actually for a 97+ Jeep, because it's about the right shape but totally wrong.

 

The pre-1991 motors used different connectors. I don't know if you'd be able to find a new replacement using your jeep's connector. They are functionally identical besides the connectors.

 

For what it's worth, my preference for replacements if mine were to fail would be to buy a junkyard one, clean the track out and lubricate it. I have lubricated '94 motors in my '91 that I converted to have power windows. The windows go up and down plenty fast and have been noise-free and reliable for years now. Even with 25 years of use on them, they're still faster to go up and down than the NOS ones I have stashed for just in case.

 

Prototype window regulator writeup that I'm writing on the spot for this thread - will complete later. May be missing pictures.

 

If anyone complains about the factory window regulators either being hard to roll up and down (manual) or slow (power) my assumption is that they haven't done this and need to. The manual window regulators are very easy to roll up or down and are plenty fast if they have been serviced, which should be done at least once in the vehicle's life or whenever they feel stiff or slower than normal.

 

This is what a "good" snake looks like. These are on my '94 OEM regulators that were more than 20 years old when I ripped them out of the junkyard and put them into my '91 years ago.

The motor (or window crank handle) is connected to a gear which meshes with the "snake" (which is just a flexible worm gear) and depending on the direction of rotation, runs the window either up or down. If the channel of this snake is obstructed by corrosion, hardened lubricant, or dirt OR the space the snake travels in is obstructed, there will be too much resistance, and eventually something (either the motor or the worm-drive "snake") will fail and the regulator will develop a dead spot.

 

The fix to this is very simple: if the window is still able to roll up and down the entire way without skipping teeth, and is just slow or stiff, the "snake" and the channel it rides in just needs to be cleaned out and lubricated. Removing the regulator can be a pain in the @$$, but once it's out, nothing you need to do is difficult.

 

Attached to the end of the snake's channel is a length of hose which is almost certainly hard as a rock by now. This is important, as it gives the "snake" a safe place to retract into when the window is fully rolled up and keeps it straight and routed correctly. On any regulator I service, I just cut it off and replace it with an equal length of new hose after I have cleaned the snake. I don't know what size it is off of the top of my head. When I did this on my trucks, I had plenty of fuel hose in the correct size left from a previous project so that was what I used. Don't forget to transfer the plastic P-clips that fit over the hose and snap to the bottom of the door frame to keep the hose routed correctly. If they are broken or not present, replace them.

 

Removing the hose will give you better access to the snake to clean it. Rolling the window up all of the way with the hose removed will give you full access to the part of the snake where the gears mesh, which is the most important part. If there is crud present in the snake, clean it thoroughly with your choice of solvent. Try not to use anything too aggressive, as you don't want the "bristles" on the snake to come off. Once the snake and the path it rides in is as clean as possible, lubricate thoroughly. I used white lithium grease, but a relatively thick waterproof grease is likely to be a better option.

 

After lubricating the regulator, before putting it back together make sure to run it up and down several times either by hand or using a 12V battery connected to the motor in alternating polarity. You should notice an immediate change in the speed of the regulator. If not, continue lubricating the snake and exercising the regulator.

 

If you have rattles in your door, the power window motors are a common source. This is an excellent time to add some closed-cell foam tape to the top "arch" of the regulator and to the motor housing to prevent it from rattling. The factory installed crappy foam and jute padding in these places, but it's probably gone by now.

 

This process has fixed every manual and power window regulator I have come across that is still able to roll up and down the entire way. If the gears are stripped, I would personally find a replacement and perform this procedure to it before installing it.

 

Here is a before and after of a very badly fouled regulator on my '91. This test was done with the engine off. The regulators are considerably faster if the engine is running thanks to the higher voltage.

After:

 

[87MJTIM]

Great write up!  Should go into the DIY section.

[coman]

Thanks very much.  Comanche club rocks

[AZJeff]

13 hours ago, Minuit said:

 

 

Prototype window regulator writeup that I'm writing on the spot for this thread - will complete later. May be missing pictures.

 

If you have rattles in your door, the power window motors are a common source. This is an excellent time to add some closed-cell foam tape to the top "arch" of the regulator and to the motor housing to prevent it from rattling. The factory installed crappy foam and jute padding in these places, but it's probably gone by now.

 

.

Good suggestions in the entire write-up, but I have a proposed BETTER solution than just the self-adhesive foam around the cable track:  wrap the foam ENTIRELY around the track, and add a small "tie-wrap" (wire tie) to keep the foam secure to the track.    Here in AZ, the heat causes the foam to come loose of the track and then fall off in the door.   The tie wrap is added security.