Swiss 2002Tii

Ignition switch powering starter at all key positions

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Hi Folks,

 

I have been in the process of swapping in the correct 220km/hr Tii instrument cluster, and servicing my clock.  All is ready.  I removed the center console and cleaned everything up, ready to reinstall.  This means that the Hazard Switch is also disconnected.

 

Last weekend, just out of curiosity, I wanted to know if I could start the motor and move the car into the sun without installing the instrument cluster...  Car turned over fine, but upon shut-off, the starter continued to get power at every point on the ignition tumbler.  I was able to find a spot between ignition tumbler points and disconnect the battery.   I've never had any ignition switch problems prior to this.

 

Today I installed the instrument cluster, car started just fine without incident, moved it into the sun (one of few sunny days where it wasn't zero degrees in months), but same thing upon power-down - starter gets power at every point.  I could find a place between points and again disconnect the battery.  When I went to reconnect the battery, I was getting power on the starter on what seemed like the whole arc of the key.  Finally found a soft spot and got the battery connected, car back in the garage.

 

Additional info: This car did not have a cold start relay circuit when purchased.  It had a button at the choke position to power the 5th injector, but it was originally wired to "On", not "Start", so it did not affect the start cycle.  I disconnected the wiring hack that was pulling power from the wiper relay, and re-wired it so that power to the CS switch comes directly from the Start position on the ignition switch.  It has worked just fine.  I built a cold start harness and relay, but it ran too long and flooded the motor, so I run the switch instead (I like it better, and even in sub-zero weather I've never needed more than a couple of seconds to turn over and run).

 

I'm looking at the color-coded  wiring diagram, and I don't see a connection through a relay or switch that would need to be in place to prevent power from circling back to the Start circuit that would cause this phenomenon.

 

Any ideas?

Edited by Swiss 2002Tii
additional info

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Sounds like you must have connected the auxiliary and run circuits together.. maybe a mistaken connector on the back of the ignition? You could try pulling fuses to try to track down which circuit is the feed??

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It could be your ignition switch failing internally. (the electrical part).  How does the spring for "start" feel?  Does it snap back easily?  Just a possibility, they have been known to fail.

Cheers. 

I tend to want to have a drink when I work on electrical wiring issues...it keeps me calm.  .lol

Matt

 

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Did this occur any time at all before you removed the instrument cluster?  And when you reinstalled the instrument cluster, did you reconnect the hazard flasher?   

 

Unless you have some wires touching back under the dash or at the starter motor, I'd suspect the electrical switch on the back side of the ignition lock.  I can't think of another place where an unswitched (hot all the time) +12v wire, a switched (ign on only) wire and the wire that energizes the starter motor all come together.

 

One more thought--the starter circuit relay...is it stuck?

 

mike

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5 hours ago, dlacey said:

Sounds like you must have connected the auxiliary and run circuits together.. maybe a mistaken connector on the back of the ignition? You could try pulling fuses to try to track down which circuit is the feed??

Thanks for your replies. 

This problem never occurred before I removed the cluster, but I did move wires around while removing the console.

 

I had the night to think about it, and it must be a crossed wire related to the cold start switch.  The  PO used the fused black/violet wire from the wiper relay, as it is a fused +12V during "On".

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I changed that wiring months ago and all worked fine.  I noted at that time that the PO had also jumpered other things off of the wiper relay, including radio power, for example. 

5ab5e55a311d9_ColdStartWire.thumb.JPG.619c94aabbbbead601ab5c723786ecf9.JPG

I noted recently that the radio wasn't working, and realized that this was because I had changed the CS switch power source from that wiper relay "On"  to a direct ignition switch "Start". 

 

Part of this project was to get under the dash and clean up/tie back these modified connections and restore the correct connections, so I'll have the chance to take another try at it today.

 

I did not reconnect the hazard flasher, but I will do so this morning before I try another re-start.

 

I'll let you know what I find.

 

BTW: My starter is a brand-new Bosch SR440X, so I don't think that would be the problem, but you never know.  The solenoid disengages properly when I release the key from position 4, and the car runs normally (until I try to shut it off).

 

I was researching this question and came across a good thread started by Rob:

Electrical and Ignition Is "The Starter Relay" Really a Starter Relay?

By thehackmechanic, September 7, 2016 in BMW 2002 General Discussion 

 

In that string Stevenola and Rob talk about introducing a relay to take the starter current load away fron the ignition... I like that.. I see another project in my future!

 

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Update... 

 

I disconnected the CS switch circuit entirely, starter still powered on all ignition switch points.  Even with the Starter connection at the ignition switch pulled, same problem.  

 

The spring feel at point 4 Start feels OK, but the switch feels funky from point 1 to 2. 

 

I have the ignition switch dismounted and disconnected.  I tested for cross-talk across the pins. Yup.  The Starter Pin 50 is shorting to other pins including the Off position.

 

Does anyone have the PN for the ignition switch ?  I don't find it in Real OEM.

 

Crap.  Not the project I had in mind for this weekend!

 

 

Edited by Swiss 2002Tii

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The electrical portion of the switch is P/N 61 31 2 682 120.  Even though the number begins with a 61, indicating an electrical part, it's located in the steering section, on pg 32-10 in the factory parts book.  That's the page with the kit of matching door locks and ignition switches, and the same page with replacement folding keys and the official BMW key case.

 

mike

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OK, I'm convinced it's the ignition switch. I shot the switch full of contact cleaner and worked it through the 4 positions.  It didn't solve the problem entirely, as the Start circuit is still shorted to the OFF and other positions, but if I pull the black-white start wire, I can connect the battery ground without triggering the starter solenoid.

The moment I connect the Starter circuit, things get jumpy.

First sunny day that I could get the car our of the freezing cold underground garage!

 

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Edited by Swiss 2002Tii
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