Got to lookin at my driver's door handle inside the door last nite and seen what appears to be a pair of wires that go up to the lock tumbler.

They are connected to a circle/ring of metal that is attached to the tumbler.

My best guess is this is the heating element to warm the lock up to thaw ice so the lock will turn.


But how is it activated?
I didnt see any switch to activate in there when the door handle is lifted.. like an e36 heated lock would work...

its activated by turning the door tumbler and holding it a few seconds I think..............E24 memory is foggy now......should be described in the manual tho......

The heater control unit has a micro switch in it that is used by both the lock heater and the interior light timer. It activates when you lift the handle. Do your interior lights have a time delay before they turn off?

http://bmwfans.info/original/images/7697_p.png (http://bmwfans.info/original/E24/Cou/635CSi-M30/USA/L/A/1986/03/mg-61/)

http://www.stormpages.com/countchocula1/bmw/bmwetm147.jpg

where is that switch located at?
I seen one right below the tumbler to different colored wiring.
There might be another down at the bottom corner...

I'm not sure about the light off delay.. I never paid attention.
But that's what it looks like allright, #2




So that heating element acts like a spacer for the tumbler system?
Or would non-heated have a different tumbler/handle, etc.?

It's activated by the handle, so it has to be in there somewhere close to it.
Is there an empty plug? Maybe it was removed if it malfunctioned and was stuck on and was drawing the battery down?
http://www.stormpages.com/countchocula1/bmw/bmwetm147.jpg

this evening I was pulling the driver door panel off the 633...


looked in and there's what USE to be a switch right below the handle on the right side.
Problem is, with the 633, the switch caught on fire! The thing is burnt to a crisp!


Dont seem to see that on the 635

Can't you trace the wires from the lock heater back to the plugs and then to the switch?

the more importent question is....


we have heated door locks? haha

Can't you trace the wires from the lock heater back to the plugs and then to the switch?


gets kinda lost when it merges into the wiring harness.





the more importent question is....


we have heated door locks? haha

I'm beginning to think they were fairly standard.

Both my 635 and the 633 have it. And the 633 was more basic than the 635 in options..

the more important question is....


we have heated door locks? haha

What were they thinking?

The door locks , the mirrors and the windshield washer jets are all heated, all set up for those snowy Bavarian winters or a nice ski trip to the Swiss Alps. But then to turn around and sell a rear wheel drive car in this price range without a Limited Slip Differential as standard equipment is pretty brain dead! :rolleyes :)

Haven't looked in the ETM, but you're saying the signal goes through the interior light relay/timer? I guess my lock heater will not work then. I had to install a jumper in place of the relay for my interior light to work.

If you look at the ETM above, the signal is FROM the lock heater control unit (the raised handle), and it activates the interior light timer, so the heater could well work. Or more importantly, your interior light timer relay might have been good and the problem may be in the micro switch in the heater control unit?

http://www.stormpages.com/countchocula1/bmw/bmwetm134.jpg

The diagram must be what's behind the red X in a box that I'm getting. When I had my door handle off repairing the lock, I do remember that the micro-switch did click on & off, but I don't remember OHM'ing it out.

I spent quite a bit of time attempting to troubleshoot the interior light malfunction. Finally gave up and just put in a jumper. Even had a spare relay/timer, maybe both were bad. The light does go on & off with the door now.

I activated mine the other night by pulling up the door handel without opening the door, they are used to thaw the tumbler in case it gets iced. The handle got warm from residual heat but the tumbler was HOT! I deactivated it, or so I thought, by lifting the handle, opening the door and closing it. I've heard stories that these are easy to burn out but it would make sense that they would run off a timer.
Dwight