FJ80 / HDJ81 Power Retracting Mirror Fix

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Apr 16, 2020
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Location
Charlotte, NC
I wanted to documented some of what I found when I went about fixing my retracting power mirrors on my '93 HDJ81 as I couldn't find a ton of information about people actually opening these mirrors up, just folks saying it wasn't worth the hassle. When I bought my truck, the passenger mirror retracted fine. Driver's side did not. Mirror adjustments themselves were fine.

Here are some threads I found useful.

I used this diagram to conceptually understand what was going on, but I found the wire colors here to be correct for the body side only, and the mirror harness itself was different.
1747756664365.png


On to the actual fixing. I took stock of and worked through a few main failure points for the mirror retraction:
- The mirror control relay (seen above)
- The wiring itself within the mirror or door harnesses
- The retraction motor itself
- The geartrain within the mirror
- The limit switches that control the motion of the mirror

- I kinda ruled out the main relay / left it for last because one of my mirrors retracted just fine.
- I never continuity tested the actual door harness, but once I pulled the mirror and opened it up I continuity tested all the leads to ensure it wasn't a simple breakage somewhere in there.
- With the mirror opened up I could remove the motor. This took 12V and spun up just fine, ruling it out.
- With the motor off the mirror, the rest of the gear train moved smoothly as I rotated the mirror, so no snags there.
- This left the limit switches as the culprit. We'll talk about how those work and how to restore function to it in a sec.

Lots of threads about how to get the mirror itself off, so I won't delve into that here. The only access notes I would add would be:
- Definitely heat up the black triangular trim that covers the mirror bolts themselves, definitely helps with removal.
- You only need to remove the front door speaker to get at the connector for the mirrors. No need to mess up the vapor barrier, etc.
- The mirror harness will be attached to a body clip that lives inside the door. I found it easier to remove the harness from this clip vs. getting the clip itself out of the door. It did not want to leave.

Working through the repair, here's a shot of the harness in its spot. You can just see the gray plastic body clip that won't come out. Remove the tape and pull the harness. Note the different wiring lead colors on the body and mirror side of the harness.

1747757772080.png


Pull the 3 screws behind the black triangle to get the mirror off. The body comes apart once you have removed the mirror itself (unscrew one screw directly in the middle of the bottom of the mirror housing) and removed 5 screws that hold it together (one on the interior surface - you have to rotate the mirror to see it and four that live behind the mirror).

Once the mirror body is off, there is a black plastic cover that simply clips on and lifts upward. There are 3 clip points. One on the front, one on the back, one on the "spine" or interior surface. With that off, you'll be able to see all the mirror retraction mechanisms.

1747758123137.png


This photo shows the lower metal gear mechanisms, and the "limit switch" itself. The limit switch consists of the white, plastic disc shown above as well as the PCB that sits on top of it and rotates (this has wires soldered to it).

1747758274130.png


In order to get this off and into the state you see above, you'll need to remove the retraction motor & housing. Remove the two screws that hold it in and pull up. Some of the geartrain might come out, but if you wiggle it carefully things will stay in place. Not the end of the world if stuff moves. The motor itself is held to the housing with one additional screw which you can remove if you need to test the motor.

So at this point if your motor spins with 12V applied and you don't see any glaring gear breakage, it's time to mess with the limit switches. This works by having the lower, round disc which is keyed to the non moving mirror base apply its contacts to the upper pcb which rotates with the mirror itself as it moves.

The limit switch itself is "indexed" or keyed to the motor housing via a small metal post, so don't try to remove the limit switch without first removing the motor housing. The limit switch itself simply slides up and off the mirror base shaft once the motor housing is removed. This is keyed to the mirror base shaft via a little slot, you can't put it on wrong. You DO NOT have to remove the circlip below the limit switch to remove anything important. I did this, and popped the whole thing apart, only to realize it's not needed.

Once the limit switch is off the shaft, you can then remove the PCB from the lower round base. It is held on by the four tabs that poke up from the round base. These can't be "retracted" until the base is off the shaft. The function of the limit switch is self evident once you get it apart - the lower contacts complete and switch the motor activation circuit depending on the position the mirror is in (remember the PCB is keyed to the mirror motion, the lower round base is keyed to the mirror base).

1747759077098.png


When I opened mine up, the contacts inside the base were just sort of rattling around. They were generally in the right place, but not making contact because they had separated from the lower round base. From the factory, these are secured in some sort of molding process. There are 2 dots and one locator shaft in the middle where plastic is formed over the contact barb. These had broken off and allowed the contact to be loose.

Continued in post 2...
 
In order to fix this, we needed to restore the contact between the lower base and the upper PCB. I opted against gluing because I hate glue. I ended up cleaning up the contacts with some sand paper (80 on the lower barbs, 3000 on the pcb just to knock some of the crud off) and 3d printing a little spacer to
that would use the pcb to help press down on the contacts and keep them in place. I also bent the contacts up a tad to help ensure good connection.

1747759347471.png


A note on the contact placement - mine were sort of loose in place when I opened the switch but be careful. I don't think you can put them in wrong (see photos for reference) but they could definitely fly out if you aren't careful when opening.

I put the switch back together with the spacers in and reassembled everything. Plugged it in for a test and voila. Even if the limit switch isn't your issue, I hope this helps folks diagnose these mirrors a little more with the additional photos & info. Cheers!

One additional note - once you get your mirror working again, verify that it doesn't touch your door molding when it folds in. Mine needed some slight adjustment in the mounting (loosen the bolts, twist it upward) to get the clearance right.

With the spacers in:

1747759482452.png


Bonus mechanism / general pics (these are missing the large pink vertical gear that actually contacts the motor which you will see when you open yours up):

1747759560190.png
1747759575783.png
 
Last edited:
Thank you so much for posting this. The folding function on my mirr
In order to fix this, we needed to restore the contact between the lower base and the upper PCB. I opted against gluing because I hate glue. I ended up cleaning up the contacts with some sand paper (80 on the lower barbs, 3000 on the pcb just to knock some of the crud off) and 3d printing a little spacer to
that would use the pcb to help press down on the contacts and keep them in place. I also bent the contacts up a tad to help ensure good connection.

View attachment 3910434

A note on the contact placement - mine were sort of loose in place when I opened the switch but be careful. I don't think you can put them in wrong (see photos for reference) but they could definitely fly out if you aren't careful when opening.

I put the switch back together with the spacers in and reassembled everything. Plugged it in for a test and voila. Even if the limit switch isn't your issue, I hope this helps folks diagnose these mirrors a little more with the additional photos & info. Cheers!

One additional note - once you get your mirror working again, verify that it doesn't touch your door molding when it folds in. Mine needed some slight adjustment in the mounting (loosen the bolts, twist it upward) to get the clearance right.

With the spacers in:

View attachment 3910437

Bonus mechanism / general pics (these are missing the large pink vertical gear that actually contacts the motor which you will see when you open yours up):

View attachment 3910444 View attachment 3910445
ors is something I always wanted to fix.
 
Of course! I hope the info helps you get there. It's a neat little feature, it seemed a shame not to get it working again considering how little was really "broken". Good luck with yours!
 

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