Sunroof trunk motor on 77 - rear cable?

CBradio · Post by **CBradio** » Wed Sep 23, 2015 8:42 pm

Just wondering,

What is the rear cable that goes to nowhere for?

I thought it was a defunct trunk opener this whole time!

Mike W. · Post by **Mike W.** » Wed Sep 23, 2015 8:46 pm

That's what drives the sunroof. The motor is in the trunk somewhere around the left trunk hinge and the cable has to go somewhere.

CBradio · Post by **CBradio** » Wed Sep 23, 2015 9:00 pm

Of course, I defer to you, BUT looking at the parts diagrams, and my car, there are two cables - one thay leaves the front of the motor, towards the front of the car, which appears to drive the sunroof, AND there is also a cable that leaves the rear of the motor, and ends just under my trunk lock, connected to nothing. It is held by some brackets that are bolted along with the top of the rear driver's side tail lamp.

Diagram is here:
http://bmwfans.info/parts-catalog/E12/U ... operation/

CBradio · Post by **CBradio** » Wed Sep 23, 2015 9:37 pm

Ah! Maybe I mis-read.

Im assuming the cable is stationary, but do you mean that the cable retracts in and out of there?

Mike W. · Post by **Mike W.** » Thu Sep 24, 2015 9:19 pm

The housing is stationary, but the cable moves within it. You really wouldn't want that greasy cable flopping around in your trunk.

CBradio · Post by **CBradio** » Thu Sep 24, 2015 9:39 pm

I see!!! I was confused, I did not understand the cable wasn't stationary.
I imagine it worked like a window motor, or wiper motor....

It happened, half my cable housing just kinda broke off and I had a friend play back and forth with the sunroof...fun too watch it go in and out.

Side note, if I can go off topic, but on the topic of sunroofs, aside from greasing up whatever portions I can access from the top of the sunroof, what else should be greased up?

LET ME REPHRASE THAT: what else can I easily reach to grease?

My sunroof is slow but working sunroof.

Lock · Post by **Lock** » Sat Oct 17, 2015 1:41 pm

CBradio wrote:I see!!! I was confused, I did not understand the cable wasn't stationary.
I imagine it worked like a window motor, or wiper motor....

It happened, half my cable housing just kinda broke off and I had a friend play back and forth with the sunroof...fun too watch it go in and out.

Side note, if I can go off topic, but on the topic of sunroofs, aside from greasing up whatever portions I can access from the top of the sunroof, what else should be greased up?

LET ME REPHRASE THAT: what else can I easily reach to grease?

My sunroof is slow but working sunroof.

Did you ever find out what to grease (and with what type)? My sunroof is completely jammed - the motor is trying because I can hear the relay clicking and the motor humming but the cables are apparently frozen.
Is there a way to manually open/close the sunroof? That particular page is missing from my manual...

RandyM · Post by **RandyM** » Wed Oct 21, 2015 4:45 pm

https://www.bmwtechinfo.com/repair/main ... 057607.jpg

RonDwyer · Post by **RonDwyer** » Sat Dec 05, 2015 7:19 pm

Ahh, sunroofs. If it doesn't leak, leave it until the spring. I usually pull the sunroof cover panel and unbolt it to remove then disassemble the entire sunroof and start cleaning and figuring out what to replace. The grease your car came with in 1981 is now as hard as Portland cement. That has to be cleaned out and properly re lubricated every 20 or so years. I like redline synthetic.

Keep my details handy, I'm in San Leandro and would be happy to show you how to do this.

Lock · Post by **Lock** » Sun Dec 27, 2015 4:02 pm

Thanks guys. I since found that the relay worked and the cables are okay but the motor itself was blown. Bought a used assembly off ebay, replaced the motor and the relay and it works again. Just in time for winter.

Although it struggles a bit so it will need to be disassembled and regreased. It doesn't leak so I'll probably leave it till spring to not temp fate.

Mike W. · Post by **Mike W.** » Sun Dec 27, 2015 8:06 pm

Lock wrote:Thanks guys. I since found that the relay worked and the cables are okay but the motor itself was blown. Bought a used assembly off ebay, replaced the motor and the relay and it works again. Just in time for winter.

Although it struggles a bit so it will need to be disassembled and regreased. It doesn't leak so I'll probably leave it till spring to not temp fate.

Early ones, meaning 79 and earlier with the rear cable, always seem slow, at least mine always did. Later ones, 80+ seem to move faster.

Lock · Post by **Lock** » Mon Dec 28, 2015 12:44 am

Mike W. wrote:Early ones, meaning 79 and earlier with the rear cable, always seem slow, at least mine always did. Later ones, 80+ seem to move faster.

Well maybe that behavior is normal then. I don't know how long the motor was dead for so not sure if it's ever been re-greased, but the movement seems to be consistent just slow. It did open fully and then initially it wouldn't move back. I thought "yeah great it's stuck fully open now, you idiot" but then on second try moved back again.
It doesn't align right automatically, so also need to figure out how to adjust the switches, but not such a big deal.

Firstfives.org

Sunroof trunk motor on 77 - rear cable?

Sunroof trunk motor on 77 - rear cable?

manual sunroof operation