3.2 conversion

[jayh]

I am in the process of converting a 1979 into a 3.2 I have two wires that I can not figure where they connect to. See photo. One black wire comes from the DME Relay and has a female spade connector. The other black wire comes from the harness going to the motor bay that also has a female spade attached to the end.
Also where does the Tach wire get connect to in the front hood section?
I checked the web sites concerning this conversion but they do not address.

[jayh]

Anyone?

[kristan]

Hi Jayh,

You will have to route about six wires from the front to the DME control unit.
See those links for help. I found them very helpful for my conversion:
Putting a 3.2 into a 73T wiring questions

http://www.pelicanparts.com/MotorCity/marcesq1/

Motronic harness questions on 3.2 conversion

You will need a Carrera Tachometer. Your SC tacho will not work.
The tachwire from the SC goes from the engine to the front. The tachwire for the
Carrera goes from the DME to the front (It is one of the new wires you have to route)
I recommend carefully comparing the wiring diagrams for the SC from this website with a wiring diagram for the Carrera (e.g. Haynes )

Good luck.

[Steve W]

To further add to the info above, there are two wires that come from the DME to the tach. Pin 11 provides injector pulse info to the upshift light in the Carrera tach, and pin 21 is what is used for the RPM gauge. Do not cross these two wires, or use pin 11 for the rpm readings or you will blow out the DME. This apparently is a common error on 3.2 conversions.

[jayh]

Appreciate the help but I still can not figure why I have 2 black wires with female connectors. In the original configuration do they connect to something? Also does it matter which way the the connect to backup terminal on the trans? Check wiring diagragram doesn't help.

[safe]

Originally Posted by kristan

You will need a Carrera Tachometer. Your SC tacho will not work.
The tachwire from the SC goes from the engine to the front. The tachwire for the
Carrera goes from the DME to the front (It is one of the new wires you have to route)

I assume the DME box use 12 volt pulses to the tacho?

When I went to EFI on my -77 I just put a diode in series with the tacho wire to block the 12v pulse, and create a virtual "ground pulse" for the tacho. Worked like a charm.
Would probably work on a 3.2 conversion.

[E Sully]

Get a continuity meter and trace the wires. When I put a 3.2 into my 73.5 I had a black from the coil that goes to the fuse panel, another black from the alarm to the DME relay, both hot in run & start. A black from the DME pin 11 for the tach upshift indicator, unused. The black/violet DME pin 21 to the tach worked fine with my original tach.

[HelmetHead]

Just from looking at that photo it is difficult to tell what those might have gone too...what color are the wires that those 6" pieces hook to from the harness (the butt connector end)?

[jayh]

The Wires are Black it looks like the one from the Pin connector to the DME is hooked up to the #6 pin