Help troubleshooting turn signals - euro m635

[dmac156]

I'm trying to get my friends m635 going, and I'm stumped on the turn signals. This car has been off the road for years, has been in the body shop for body work and paint, so anything could have happened. Here's the situation:

Emergency flashers
- rt blinkers work correctly (front and back)
- lt blinkers do not work at all
- I have power at terminal 3 (always on)
- I have power at terminal 1 when the key on
- the dash lights light up when the button is pushed, and the license plate lights light up. If I remove terminal 7 it goes out
- I have tried 2 different flashers with the same results

Turn signals
- nothing is working on the turn signals
- I do not have power coming in on green/yellow or green violet when the key is in the accessory mode. I can't find power on any wires going into the stalk

Fuses are good on fuses #4 and 24

Based on the wiring diagrams (see link below), it looks like it gets powered through the hazard switch, but when i check the gn/vl wire coming out of the switch, I don't have power there. Can anyone verify that the green/violet wire is the only power source for the blinkers (normal operation)

https://www.bimmerforums.com/forum/s...ht=turn+signal

If anyone has any ideas, please post them here, or PM me if you want to talk on the phones.

[Bert Poliakoff]

Quick question Did I miss something or did you not mention power going into the switch? These switches do go bad so how about jumpering around it I had the same problem on my 81. Bad hazrad switch was the answer. On the early cars they can be taken apart and the contacts set with more tension but I went new

[dmac156]

Quick question Did I miss something or did you not mention power going into the switch? These switches do go bad so how about jumpering around it I had the same problem on my 81. Bad hazrad switch was the answer. On the early cars they can be taken apart and the contacts set with more tension but I went new

Hi Bert, I have power to the hazard switch, both the always on from fuse 24 and the switched from fuse 4. I have no power to the blinker switch (attached to the stalk). I have checked the blinker switch for continuity, and that continuity looks good.

[Bert Poliakoff]

So what happens if you by pass the hazard switch?

[dmac156]

How would I do that? Connect one of the powered leads directly to green/violet?

[dmac156]

I took the switched power lead from the hazard switch, connected it to the blue/red wire, and the front and rear left lights came on solid. So that is good news.

Now I can switch the blue/red and blue/black on the hazard switch, and get either the lt or rt side to flash. That would make me think it was a bad hazard switch, but I've tried 2 switches,
and I get the same behavior on both switches.

[carsnplanes]

Did you bypass it by jumping the terminals within the hazard switch base/connector or way before and way after it? Perhaps the hazard switch base has loose terminals.

[dmac156]

20200910_082749.jpg

Something happened to the connector, you can see that it got hot and melted at some point. I removed all of the spade connectors from the housing, and put them back on the hazard switch individually. So I was able to just remove the two connectors and jumper them.

Note: I have a new housing being shipped to me, so when this goes back in permanently it will have a proper housing.

[dmac156]

Problem solved. I'll document what I found for people who find this thread in the future.

It turns out that whoever installed the connector on hazard switch installed it backwards. I didn't think that was possible since it's keyed, so that was not the first place I looked.

Once I swapped the connections, all the flashers worked, all the weirdness stopped (like the instrument panel lights lighting up), and it probably explains why the connector housing was burnt (see picture above).

The hazard has to be installed in order to feed power to the blinker switch.