2.7 "i" cluster/wiring question...(pics included)

[e30project's101]

Hey all.

I did the 2.7 "i" swap. I used an 86 325e complete car and put all the "i" goodies on from an 88 325i...including the complete "i" wiring harness and ecu (027)

under the dash there is a black connector that comes out of the "i"harness, and three connectors coming from dash.


I understand you need to hook up one or all of these to get the tach to work (or whatever else), what do you guys think?..and of course anything else they do let me know what to connect!

[jlevie]

I think your 86 car would be like my 87 325is and it had three connectors from the car that connected to the engine harness. Those are:

Single wire connector with a red tag and a violet/black wire - A/C input to DME pin 41

Single wire connector with a white tag and a blue/green wire - Speed signal to DME pin 29

A three wire connector:
blue/back - Tach to DME pin 6
green - Start Input to DME 27
white - Econometer to DME 32

The 88 harness routes those wires that earlier cars had on the three wire connector to C101, as follows:
Tach - C101 pin 9
Start input - C101 pin 7
Econometer - C101 pin 6

The engine won't start without a Start Input signal to the DME, so at the very least you'll have to modify the this harness to supply that signal. While at it you can also tap in the Tach and Econometer signal.

You will also want to open the harness side of C101 and cut the wire going to pin 20, or else you will melt the wires going to the main relay when you try to start the car.

I never bothered to trace out the A/C input or Speed Signal connections as my car is a race car that doesn't have A/C.

[e30project's101]

The engine won't start without a Start Input signal to the DME, so at the very least you'll have to modify the this harness to supply that signal. While at it you can also tap in the Tach and Econometer signal.

You will also want to open the harness side of C101 and cut the wire going to pin 20, or else you will melt the wires going to the main relay when you try to start the car.

Thanks for the info!!!, I have been runnning (not driving yet) the car with all of those disconnected...mabey it's slightly diffrent than the other harness?

[jlevie]

If you can start the engine your's must be different. In that case the wiring diagrams at http://wedophones.com/BMWManualsLead.htm should be useful in sorting things out.