92 Toyota Previa rear sunroof

[Johny]

I have a 92 Previa that's in good shape. The only thing that's not working is the rear sunroof. When I push the switch to open it I can hear the motor run. It sounds like it runs smooth and without a load but the roof does not move. Last year I took some of the vents off the rear air conditioner but when it looked like I would have to remove the rear AC I just put it all back together. Anyone had this problem and know what it might be and what if the rear ac must be removed to fix the roof? Thanks for any help...

[originalkwyjibo]

Not sure if it applies to Previas but in the van owners manual it explains how to remove a screw to disengage the motor and close the sunroof manually in the event of a motor failure. If it has this feature perhaps the screw is loose or missing.

[Johny]

I think I tried that in the past and gave it another try today. Manual says to remove the screw but I'm only able to unscrew it but not able to remove it. Anyways once unscrewed you can engage the motor shaft to open/close the sunroof. I believe this is in case the motor fails. In my case the motor works but the roof does not move. However the roof is coupled to the motor I think this is what failed. I'm afraid to get to this problem I need to remove the rear air conditioner. Just not sure if its worth the trouble or if the parts will be available to do the repair.:cnfsd: Thanks for the reply tho..:)

[cvtroger]

I posted this in another thread, and I am unsure if it pertains to you completely,

but

http://reactionprevia.blogspot.com/2015/10/removing-rear-moon-roof.html


When you do find the issue, please post it. Solving these issues helps others that might come upon the same problem.

Good luck

[Johny]

Roger, thanks for posting but this video shows how to remove the glass roof. I think I need to get to the drive mechanism. Just not sure if its worth removing the rear AC unit. Was hoping some one had already been though this but I can't seem to find much. Frustrating because I have my parents old '84 toyta van on a farm. While its not driven on the road it still work well including the large rear sunroof. The 84 must have been a better design. I think on the Previa what happened was that I didn't keep the tracks well lubricated and the motor seem to have striped out whatever its connect to to drive the roof.

[originalkwyjibo]

Maybe this will be of some help: http://www.toyotavantech.com/forum/showthread.php?977-Rear-sunroof-on-Previa-Estima-vans

[cvtroger]

Roger, thanks for posting but this video shows how to remove the glass roof. I think I need to get to the drive mechanism. Just not sure if its worth removing the rear AC unit. Was hoping some one had already been though this but I can't seem to find much. Frustrating because I have my parents old '84 toyta van on a farm. While its not driven on the road it still work well including the large rear sunroof. The 84 must have been a better design. I think on the Previa what happened was that I didn't keep the tracks well lubricated and the motor seem to have striped out whatever its connect to to drive the roof.

Okay, Maybe this video?

https://youtu.be/OuqEEiHgN5g?list=PL5q_8kLVTuqLa8ICIVQa1E_sfirAHnz0 y

I removed much of the rear AC unit, but I think next weekend, I will fully take out the A/C unit and check the rear moonroof motor just for myself.

If you do figure it out, please post it so it's archived!

[Johny]

Maybe this will be of some help: http://www.toyotavantech.com/forum/showthread.php?977-Rear-sunroof-on-Previa-Estima-vans

This post didn't make a lot of sense to me:cnfsd: Not sure what plastic arm he's talking about. I know I can't move my sunroof by hand....

[Johny]

Roger, That video helps some. I have never done much work on Ac units. I have the 92 which uses the older refrigerant I believe. Not sure if its still on the market. I have the service manual but there is not much in there on the moonroof. Still trying to figure out the issue before putting in too much time and effort which may not be possible:wall:

Here are two pictures of the sunroof motor I found on the net. The second picture shows the screw you can access from under the switch pannel. This is used to close the roof when the motor fails. My motor runs and the screw turns when I run the motor but the roof doesn't move when the motor runs or when I manually turn the screw. In the first picture you can see the output shaft. I'm guessing my problem is either between the gear with the screw and teh gear with the output shaft or with the coupling between the outout shaft and the roof. If the problem is in the gearbox assembly, I should be able to just replace the motor/gearbox. If its in the output shaft/ roof coupling then I may need parts that may not be available. Inspection may be the only way to determine the issue. Wish teh service manual had more on the moonroof :bdmd:3015 3014

[Johny]

Here's some info I found on the 92 AC refrigerant...
http://repairpal.com/what-kind-of-refrigerant-freon-should-be-used-for-a-ac-recharge-376

After further research it seems like some of the AC components may need to be replaced if converting to r134a from r12. On the other hand r12 seems to still be available on ebay.

BTW here's a picture of my Previa with ~72,000 miles.

3018

[cvtroger]

Went the junkyard and got more info. Two weeks ago, I was taking out the rear moon roof and started to do the head liner.

But today,



https://youtu.be/IUtsGRF_5fo

[originalkwyjibo]

I think your rear a/c roof "unit" is nothing more than ducting and fans. There doesn't appear to be any refrigerant to the part in the roof. This is how the vans are as well.

[Johny]

Roger, nice work :thmbup:. Wish it was easier to get to the motor. Still have not figured out why my roof doesn't open. Wish there was some way to determine if the final pinion gear is turning without tearing everything apart. Were you able to remove the motor on the van? What is the pinion gear turning when the motor runs? Could this coupling strip out if there is too much drag on the roof? Also, when you moved the AC equipment out of the way did you have to open any lines that would cause a lost of refrigerant?

[originalkwyjibo]

My bad. I see now after looking at a parts diagram that you do have an evaporator coil in the roof. Maybe cvtroger can provide insight as to whether this is plumbed with hardline or flexible hoses. If it's hoses you may be able to pull down enough for access without opening the system.

[Johny]

If it's hoses you may be able to pull down enough for access without opening the system.

From the video it looks like it may be possible to access the motor without removing the head liner (just remove the AC equipment). Hard to tell by looking at the video. Thanks again for posting it Roger:clap:

[cvtroger]

Roger, nice work :thmbup:. Wish it was easier to get to the motor. Still have not figured out why my roof doesn't open. Wish there was some way to determine if the final pinion gear is turning without tearing everything apart. Were you able to remove the motor on the van? What is the pinion gear turning when the motor runs? Could this coupling strip out if there is too much drag on the roof? Also, when you moved the AC equipment out of the way did you have to open any lines that would cause a lost of refrigerant?


I didn't remove it, but should have! I just looked at it. But hopefully next week it's there and I'll check it out. As for troubleshooting it... I don't, that is more technical than my basic knowledge knows.

I didn't look at the A/C lines, maybe I should have. There is this black gooey material wrapping the coolant lines. I just bent it, but you know what, I'lls ee next week.

I was in a rush because it was getting to closing time and I had to get his GTO center piece off of a 3000gt.

[Johny]

https://www.youtube.com/watch?v=zXgK3XWhKbM

Here's a video showing the removal of a '92 Corolla sunroof. I think the design and motor are very similar to the Previa. After watching the video I believe the problem with my roof is one of two things. 1)... the out put pinion shaft from the motor gear box in not engaging the drive cables or 2) the cables have come loose from the carriers. Still debating if is worth trying to fix something that was seldom used:dizzy: Removing the tracks looks like it could be a big job:doh:

[cvtroger]

I'll be going to Canada again this weekend, but I hope it is there when I get back.

I'm going to do a video on removing the head liner, front sun roof and other things.

A salvage shop in Malaysia (the owner is a friend) has stripped tons of previas and often times, he has pictures of pieces for sale. He had the whole rear moon roof deal out.

I'll try and do that next weekend.

[terbennett]

Sorry I'm late to the party. I am willing to place bets that your issue has nothing to do with the motor. I bet it's has to due with the actual cables that move the rear sunroof. These are fairly common parts that fail. The cause is generally a sunroof that is never used , but the could fail for other reasons as well. The reason is usually lack of lubrication. Most people don't use the sunroof enough to keep the systems properly lubricated. Since most of the mechanism is exposed to the elements, the lubrication dries up and causes cables to fail. Make sure to by them ised. Last I checked, Toyota wanted over $700 for them. Good luck.

[cvtroger]

Sorry I'm late to the party. I am willing to place bets that your issue has nothing to do with the motor. I bet it's has to due with the actual cables that move the rear sunroof. These are fairly common parts that fail. The cause is generally a sunroof that is never used , but the could fail for other reasons as well. The reason is usually lack of lubrication. Most people don't use the sunroof enough to keep the systems properly lubricated. Since most of the mechanism is exposed to the elements, the lubrication dries up and causes cables to fail. Make sure to by them ised. Last I checked, Toyota wanted over $700 for them. Good luck.

Thanks for that tip!