Interesting e34 electrical observation.

[Russell]

Interesting electrical observation. For several months I could not read the codes with my Peake tool. Neither could my Indy. The only significant electrical changes to my car were a used cluster swap and I added a electro chromatic (ec) mirror from an e38 (the one with a 10 wire connector).

I not see how the cluster could be the problem as it was from the same year car and I swapped out the coding plug .

Then I removed the ec mirror and everything worked perfectly. Apparently I did not disconnect enough of the 10 pin wires to keep it from messing up the ability to read codes. I will do a little more research and see if I can make the ec mirror work AND read codes next spring.

[genphreak]

Is the mirror factory fitted? What type- the one with the slider, or the auto only version?

[Russell]

Is the mirror factory fitted? What type- the one with the slider, or the auto only version?

The mirror I added was a stock e38 auto ec mirror. My 525i had a manual day/night mirror. Is this what you are asking. All US 95 e34s have a ten pin mirror connectors. However the connector is used for the 540i type of security system. Not sure if any of the stock 540is had an ec mirror.

[genphreak]

Indeed. The firmware programming for the modules relating to rear vision mirrors is a mystery to me. I have 2 euro '95 e34s with EWS and DWA IV, one 525i touring has the auto ec mirror, the 540 on the other hand has the early one with the slider (though it was made a month after the touring).

However when swapping mirrors on an e34 (with transponder or programmable alarm keys), the fact that the transponder key programming works through the damn mirror is something that is worth checking afterwards. I haven't seen any write ups on that part yet. I imagine yours is pretty much as per http://www.bimmernut.com/forum/5-series-bmw/42822-e34-factory-options-guide-300-pages.html, except that your car is a 95? It would be worth checking your car's wiring diagram/TIS and sharing what you find. I imagine the TIS/EBA would have a procedure for doing this and re-programming any modules if it is indeed necessary.

[Russell]

You only need to connect pin 1 - reverse, pin 3 - positive and pin 10 - ground to operate an EC mirror on the 95 US 525i per Q from bimmerboard. You might search for his post as awll as Shayne's posts. In my case the mirror worked well. However one or more of the other 7 pins appear to be cause "electrical confusion" and prevent the code reader form working properly. I believe I just need to identify the offending pin and remove it and all will be well with the code reader and EC mirror.