Jump to content
HybridZ

BMW Temp Switch Questions


Recommended Posts

I'm wiring up my electric fan in the Z, using the Ford Taurus fan.  My question is about the BMW temperature switch.  Mine has 3 wires, I presume a high temp, low temp and ground.  I wasn't sure which wire was which, so I started my car warmed it up and put my multi-meter across all the connections.  I'm presuming it would just close the circuit, but I'm not getting any continuity across any of the pins.  I started it back up and basically red lined it on temp and still nothing.  Is my understanding how this thing works incorrect?  Do I need to ground the housing?  Do I have a bad sensor?

Link to comment
Share on other sites

You are correct in your assumption that one leg is the signal ground and the other two pins are the high and low signals. There should be continuity across the common pin to the low pin at its switching temp as well as the high at its switching temperature.

 

If you aren't getting continuity across any of the pins it might be fair to say the sensor is bad.

Link to comment
Share on other sites

Got my new sensor in and it's working, but I can't figure out the pinout.  I ran the car up to temp and they all 3 seem to make continuity at the same time.  I get that 15 degrees isn't a lot when you're around 200, but I would have thought I'd at least be able to figure which is ground.  Doesn't seem to matter which two I connect, they all beep my multi-meter.  Anybody know the pinout of this?  I've tried searching online, but can't seem to find one.  I checked the forum, but maybe I'm not looking for the right key words.

Edited by Witchboard
Link to comment
Share on other sites

Okay, I found it.  Just for future reference, the brown is ground, black is high and purple is low.  I tested it just to make sure this evening.  I turned off the engine before it reached temp and let it creep up while shut off with my multi-meter connected.  Should be able to finish up my wiring tomorrow.  Had to come in because the mosquitoes were trying to carry me away.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...