o2 sensor wire has voltage ?

[jordan325ic]

First off, I apologize if this isn't the correct section. I know MS1 is a bit old but I couldn't find anywhere else to put this thread. I believe my question falls under general troubleshooting.

Car: Turbocharged 1988 BMW 325is.
MS: MS1 v3.0 custom built to plug directly into the stock ECU box, plugging into the wiring harness with minimal modification.



Ran for a few thousand miles with no trouble, all sensors appeared to be functioning correctly via the megatune dash. Then the car sat for 2 years while I was out of the country. When I got it running again the LC-1 wideband appeared to not function. Neither the dashboard gauge or Megatune was giving me a reading at any time (random readings, mostly pegged at 22.4 or 9.0). Recalibrating the sensor, replacing the sensor and replacing the controller did not fix anything.

During my troubleshooting, I discovered that the wire that connected the megasquirt harness to the LC-1 was charged with battery voltage (13.0v) even when MS was completely disconnected from the LC-1. (pin 24 I believe).

I thought the LC-1 is supposed to provide the signal voltage (0-5v). Should the wire coming out of the MS be hot if it's not connected?

[DonTZ125]

The O2 wire should receive 0-5v from the WBO2 controller. Vbatt coming OUT of the MS on that wire is a sign of Very Bad Things(tm). It may be the angle of the photo, but your wiring to the ECU connector seems rather dangerous to me, with many opportunities for shorts and cross connections.