R34 GTT Sunroof Motor Repair/Replacement

[GoHashiriya]

Hi all,

I've recently been suffering from a buggered sunroof motor; it works a bit, then not, then will stay half open until I hex key it back into place. I pulled the sunroof motor from its mount and tried running it with the interior buttons and it acts the same.

Now, I've been having a nightmare trying to find a replacement, it's the same unit in the S15, Z10 (cube) and R34 - Nissan discontinued it in 2013. I've searched breaker's yards in the UK, Japan, Aus and Canada to no avail. I don't want to leave it as a dud. 

Is it possible to have something like this repaired by an electric motor wizard of some sort? Who would you go to for something like this?

Any suggestions on how to fix it would be great. I'll consider getting a plexiglass window fixed in there if I fail entirely with this.

[GTSBoy]

Given that the motor will be dismantleable, why not take it apart and have a look at what might be wrong inside it? Could be a lack of lube on the pinion, could be a lump of crap running around and getting jammed in the teeth. Could be the motor's brushes that need a touch up (in which case, yes, an electrical guy could look to fix it for you.

There's a whole roof on ebay at the moment for $850.

[Millerman]

Amayama may have a listing for the motor seperately?

[GoHashiriya]

On 10/3/2021 at 10:51 AM, GTSBoy said:

Given that the motor will be dismantleable, why not take it apart and have a look at what might be wrong inside it? Could be a lack of lube on the pinion, could be a lump of crap running around and getting jammed in the teeth. Could be the motor's brushes that need a touch up (in which case, yes, an electrical guy could look to fix it for you.

There's a whole roof on ebay at the moment for $850.

It's been a while GTSBoy, but I did heed your response. Today I found the time to pull apart the motor, after printing a bracket which holds the sunroof shut.

It was fairly simple to dismantle, I took some pictures so I could remember the positioning of the gears/switches. 

From what I can tell, the gearing seems intact, spinning the commutator turns the gears with no resistance. 

The brushes, well, they're definitely there. They've worn at an angle - see pics - although, as an engineer only by degree, which was a while ago now, I don't have the XP to know how badly worn brushes need to be to cause intermittent running problems. From what I know, it's usually the brushes or switches that die. Does the wear on the brushes here say anything to you? 

On 11/13/2021 at 6:12 AM, Millerman said:

Amayama may have a listing for the motor seperately?

Nope, out of stock - Nissan discontinued it around 10 years ago.

[Millerman]

Have you tried powering it off the car? 

[GoHashiriya]

On 11/24/2021 at 6:28 PM, Millerman said:

Have you tried powering it off the car? 

Hahaha, yeah I pulled it from the rack and tried operating it. It works very very intermittently, like will spin a half revolution then stop then may move again if I relentlessly press the buttons. Could be a switch that’s busted but works the same whether I’m using the tilt function or slide.

[PLYNX]

Had this happen to me on various electric motors over the years

I've have success with putting the armature into an electric drill and polishing it with 1200 grade sandpaper.

This will take the build up of carbon and dirt built up over the years on the copper.

Reassemble then see how it goes.

If this fails then you will have to look at the brushes as they can, as well, build up gunk and oxidize and fail to take the current to the armature.

If its the brushes then all I did was go to and electrical repair shop, for power tools, with a set of vernier calipers and went through brushes until I found the right size and soldered them into place.

If this fails then you've got to look at the armature or the winding itself and an electrical repair shop is going to have a poke and a prod at it.

My money says its the brushes

[Millerman]

On 24/11/2021 at 11:57 PM, GoHashiriya said:

Hahaha, yeah I pulled it from the rack and tried operating it. It works very very intermittently, like will spin a half revolution then stop then may move again if I relentlessly press the buttons. Could be a switch that’s busted but works the same whether I’m using the tilt function or slide.

Ok i was meaning completely off the car and running it with just a battery to see if it operates differently. Looking at your photos it looks like everything is in good nic. Unless there is a small wire fracture perhaps inside the motor id be guessing its the switch has dirty contacts or something along that line. If you power it up direct from a battery then you can prove if its the car or motor thats causing the fault.

[GTSBoy]

That commutator does need to be cleaned. It is very glazed. You need to make sure that there are no bridges of conductive material between the commutator's pads also, especially if you machine/shrop the comm.

Those brushes appear to be ~50% worn, or more. They might not have enough tension to make reliable contact with the commutator, and the fact that they are so short and are sticking out of their recess so far is probably the reason why they are worn on an angle. I'd suggest it needs new brushes.

[GoHashiriya]

On 11/25/2021 at 8:15 AM, GTSBoy said:

That commutator does need to be cleaned. It is very glazed...

 

On 11/25/2021 at 5:03 AM, PLYNX said:

Had this happen to me on various electric motors over the years...

Ahh, thanks both for this info. I will be paying some attention to the commutator and brushes in the coming days. I managed to order some brushes off amazon after measuring with a vernier. They might be a touch on the long side (14mm vs the 9mm OEM) but we'll see - appparently brushes can be sanded down. 

PLYNX, thanks for mentioning how you polished up the commutator. Fortunately I do have a drill lying around, along with a dremel that may prove handy for polishing. I'll see what's more suitable, of course I don't want to be using something too aggressive.

Cheers GTSBOY, what I couldn't make out is that half of the face which contacts the commutator matches the surface curvature of the commutator, yet the other half has been worn away at an angle. See pic below.

It seems that most of what is mentioned here is something I'm able to do, so I'll proceed with this for now. Looking at the windings in more detail will require a professional. 

On 11/25/2021 at 6:04 AM, Millerman said:

Ok i was meaning completely off the car and running it with just a battery...

Ahh, yes I see. And that's a great point. I haven't done this as the motor having two input plugs just seemed a bit daunting. - one goes to the harness and one goes to the interior switches. Perhaps it's still possible to drive the motor using an external power source and using the interior switches.

For sure a switch repair is beyond me so that will require getting my head back in the old Neehongo textbook and figuring out how to converse with the electronic stall people at the market.

Thanks for the responses! I'll update with how I get on with the commutator/brushes/power supply. 

[GTSBoy]

On 11/25/2021 at 3:35 PM, GoHashiriya said:

of course I don't want to be using something too aggressive.

You don't even need a drill. Just cut a strip of sand paper (or even better, stropping tape) wrap around one side of the commutator so that you're holding both ends of it towards you and just do the old back and forth on both ends. Wiggle them up and down so you strop more than just the far side. Then rotate the armature (your assistant, or the vice, however it is being held) a bit and keep going until you have done an even treatment all the way around. Don't try to deglaze each spot all at once. Better to treat it like doing light coats of paint and go around and around a few times.

If you use a hand drill to spin the armature, be very bloody careful. One slip and you can make a mess of yourself. If you use a drill press it will be easier and safer, but still a little prone to risk. A lathe is one step better again (and how proper reconditioners would do it).

[GoHashiriya]

On 11/25/2021 at 2:15 PM, GTSBoy said:

You don't even need a drill. Just cut a strip of sand paper (or even better, stropping tape) wrap around one side of the commutator...

Hahaha yeah, may end up launching the thing through the paper-thin walls of my dumb Japanese house. Will go at it by hand via the aforementioned method first.

Brushes will arrive this weekend - hopefully they fit, as the connector comes from the rear on the new ones, as opposed to the side. From my judgement it shoudn't interfere with the spring. 

[GTSBoy]

Use a round file or a bit of sandpaper on an appropriate sided dowel to give a bit of shape to the brushes if you need to shorten them.

[GoHashiriya]

So just to update: I changed the brushes over and polished the commutator using a 1500 grit sanding sponge; it was super easy to polish being copper. A power tool wasn't necessary, although could have made it easier if you have the finesse to use it well.    

Yet this was to no avail, the motor worked as it did before, stop, start, stop start, etc. Today I went to my mechanic's shop to do a few things. I showed him the motor and asked in broken Japanese "who can fix this?", he took it from me and had a crack, was able to fix it-ish. From what I could understand (which is very little), the problem with the motor was with the clutch disc located amongst the gears, I saw it whilst he was working but couldn't identify any issues.

I say he fixed it-ish, because now the motor will run continuously when free from the rack, which is great. But once I had reinstalled it, the tilt function would work but the sliding function sounded off, like the motor was under more load than before and the motor was struggling. We're going to pull apart the rack in the new year and see what we can find. 

Hopefully this is of some help to others that get sunroof motor issues with their R34, S15 Silvia, or highly unlikely the Z10 cube. I will update this when more progress is made.

[GoHashiriya]

I managed to find a used motor and bought it just for peace of mind. Well, it didnt help at all, the issue still persists. This one seems to have different quirks, perhaps it's also a dud. I need to pull the rails out and test the switch. The issue is perhaps something to do with the sliding mechanism.

This won't get fixed in a hurry because pulling the sunroof out and leaving the car with a hole in the top is a bit of a pain without a garage/secure parking.

[GoHashiriya]

So, great news. Today I pulled the rack and "fixed" the sunroof. The issue with the binding mentioned a couple posts above was that the wind deflector arm hadn't been fastened to the rail correctly. This either occured when we first pulled the rack and reassembled everything super quickly to make it to a mate's BBQ (likely) or it was knocked by some other means. There was also some slight deformation where the arm fixes to the rail, probably caused by incorrect installation and then binding against the sunroof guide.

The used motor I bought is still a dud, I'm using the original motor that my mechanic worked his magic on. The second motor seems to work intermittently, sometimes slides a little, sometimes tilts a little, but yeah, it doesnt work. I would actually like to fix this one to keep as a spare; so when I get time, I'll also take this one apart and see what's wrong with it. 

It does seem as though the initial fault was caused by the motor, then my d*cking around with it caused the sunroof to not retract properly. You won't be able to buy a new motor, Nissan doesn't stock them anymore, and the company that produced them - based near me in Gifu - seems to only deal with corporate clients. If/when I can dismantle the second motor to find the fault I'll post the result here.       

[niZmO_Man]

Nicely done. Thanks for the updates.

Curious if the motor would be similar 90's Japanese cars, surely Nissan didn't specify a unique motor just for those models you listed...

[GoHashiriya]

On 5/5/2022 at 7:45 PM, niZmO_Man said:

Nicely done. Thanks for the updates.

Curious if the motor would be similar 90's Japanese cars, surely Nissan didn't specify a unique motor just for those models you listed...

Yeah I would think the same, all I did was use Amayama to tell me which models the part number was suitable for. Although, on my quest for a motor, I never did see anything which resembled it entirely. Nissan was a huge loss maker back in the 90s (possibly still is), perhaps things like this is why.

[GoHashiriya]

So before I put the headliner back in I thought I'd give the sunroof motor a good workout to ensure it works consistently, and guess what, It opened and got stuck. It started exhibiting the same sort of problem as the second motor I bought. After a few minutes it worked - the sunroof closed - then it worked seemingly well for a bit and got stuck.

Instead of pulling apart the motor I thought was fixed, I decided to take a look at the second motor. Tested continuity across the board, tested the switch (in the car) and it all checked out okay. That's when these two little buttons inside the motor got my attention. In short, bottom button pressed, sunroof opens, left button pressed sunroof closes. No buttons pressed, tilt function works (motor works in forward and reverse). 

The buttons are operated by this white gear, so it seems that the timing is off with the gear, or something is worn, not allowing the button(s) to be fully depressed at the correct time.

What I can't seem to get my head around is how the motor switches between tilt function and sliding function, as the open (sliding function) button/switch must be both closed and open simultanously - only tilt or slide works at one time. As there seems to be no third input here. That's where the little copper spring may come in, although it really doesn't seem to move.

Any input would be greatly appreciated.

    

  

 

[GoHashiriya]

Just incase anyone ever goes down this rabbit hole. I contacted Mitsuba and got the following response, it's as expected:

 

Dear Mr. Perry

This is Mishima in Mitsuba.

I'm sorry for replying late.

Firstly, we apologize for the inconvenience, but currently we cannot help provide you with any design information and sell to anyone other than the vehicle manufacturer due to the transaction contract with the vehicle manufacturer.

As you know, the authorized Nissan dealer do not sell these motors.

We have no idea about it.

So we apologize for not being able to meet your request.

We would like to hope your kindly understanding our position.

 

ミツバの三島です。

返信が遅くなり申し訳ございません。

まず、誠に申し訳ございませんが、現在は車両メーカーとの取引契約により

設計情報の提供や車両メーカー以外への販売ができません。

ご存じの通り、日産様の正規販売店はすでにこれらのモータの販売をしていません。

我々にはなす術がありません。

よって、ご要望にお応えすることができず申し訳ございません。

何卒ご理解賜りますようお願い申し上げます。

 

 

If you can be f*cked, get in contact with Nissan and then Mitsuba. I was requesting design information or a replacement. Of course I understood the likelyhood of getting this.