993 to 964 Under Seat Connector Pin 7 Question

[drola]

This is a long shot but here it goes.
I am putting a 1995 993 OBD1 motor in my 1990 C2. I have everything figured out except one little pin that is driving me nuts.
Under the passenger seat there are 2 connectors on the 964. One is a 6 pin (of which only 3 pins are connected) and the other is a 14 pin.
On this 14 pin connector, on the 964, pin number 7 is a green/blue wire that goes from the ccu to the dme and has something to do with the a/c relay and resistor, according to the wiring diagrams.
On the 993 harness, pin number 7 on this same connector is a brown/white wire and goes to the dme for some sort of tiptronic coding. And looking further into it, seems to possibly be a ground.
I'm afraid that if I just leave it alone, I may short circuit something. Most likely the ccu.
Has anyone dealt with this? Should I just remove the pin from the connector and leave that tiptronic coding wire disconnected?
There is nothing in the 993 harness that would take the place of the 964 green/blue wire.
I really don't want to fry anything.
Thanks in advance for any suggestions

[Bill Verburg]

Originally Posted by drola

This is a long shot but here it goes.
I am putting a 1995 993 OBD1 motor in my 1990 C2. I have everything figured out except one little pin that is driving me nuts.
Under the passenger seat there are 2 connectors on the 964. One is a 6 pin (of which only 3 pins are connected) and the other is a 14 pin.
On this 14 pin connector, on the 964, pin number 7 is a green/blue wire that goes from the ccu to the dme and has something to do with the a/c relay and resistor, according to the wiring diagrams.
On the 993 harness, pin number 7 on this same connector is a brown/white wire and goes to the dme for some sort of tiptronic coding. And looking further into it, seems to possibly be a ground.
I'm afraid that if I just leave it alone, I may short circuit something. Most likely the ccu.
Has anyone dealt with this? Should I just remove the pin from the connector and leave that tiptronic coding wire disconnected?
There is nothing in the 993 harness that would take the place of the 964 green/blue wire.
I really don't want to fry anything.
Thanks in advance for any suggestions

964
the 2 pin is always empty

the 3 is empty when a cat is installed, bridge to battery + for Ca & J, bridge to ground for no catalytic converter

993 has only a 2 pin
RoW w/ cat is open
RoW w/o cat has a 1 kohm plug 944.612.492.00
US & Canada has a wire harness to ground


on tips the DME is cided w/ a tip wire harness

[drola]

Thanks for chiming in Bill. But I think you are referring to the pigtail on the harness close to the dme connector.
I'm talking about the 14 pin connector under the driver seat. Pin 7 on the 964 chassis side has a function with the a/c relay and resistor. Pin 7 on the 993 harness is for tiptronic coding.
Do I just pull pin 7 out of the 993 harness side and leave the 964 chassis side pin 7 open?

[Bill Verburg]

Originally Posted by drola

Thanks for chiming in Bill. But I think you are referring to the pigtail on the harness close to the dme connector.
I'm talking about the 14 pin connector under the driver seat. Pin 7 on the 964 chassis side has a function with the a/c relay and resistor. Pin 7 on the 993 harness is for tiptronic coding.
Do I just pull pin 7 out of the 993 harness side and leave the 964 chassis side pin 7 open?

I will have to go look at the wiring diagrams

it would help if you could id the specific 14 pin connector

the 2 main ones are X4/1 and X4/2 but i would need to find the component locator map which has eluded me this AM

pin 7 of X4/1 is the trans input pin 51 on the DME, I don't think this is used w/ a manual trans, but I could be wrong because pins 42 & 44 on the DME are also tip related. 42 is the tiop stepping switch and 44 is coding

[drola]

Sorry Bill, the pin 7 is in the X4/2 connector. Yes indeed it goes to the 993 dme pin 44 for tiptronic coding. Connector X4/1 gets disassembled and converted into the 6 pin connector T15 of which only 3 pins are used.
But on the chassis side on the 964 connector T16, where this X4/2 plugs in to, the same pin 7 goes to the 964 dme pin 41 for a/c relay and resistor function.
I am replacing the 964 dme with the 993 dme so I don't want those two circuits to clash and cause any sort of problem.

[Bill Verburg]

Originally Posted by drola

Sorry Bill, the pin 7 is in the X4/2 connector. Yes indeed it goes to the 993 dme pin 44 for tiptronic coding. Connector X4/1 gets disassembled and converted into the 6 pin connector T15 of which only 3 pins are used.
But on the chassis side on the 964 connector T16, where this X4/2 plugs in to, the same pin 7 goes to the 964 dme pin 41 for a/c relay and resistor function.
I am replacing the 964 dme with the 993 dme so I don't want those two circuits to clash and cause any sort of problem.

On the 993 wire diagram I' looking at pin 7 on X4/1 is trans input
on X4/2 it's MAP coding

I haven't dug out the full set yet, I'll try to do that this PM

[Bill Verburg]

Ok just looked at the wire diagrams in the manual, apparently both plugs are under drivers seat(LHD) and pin 7 0n X4/2 is map coding, but I have a hand written note that this is for tip only. I don't remember writing that but it is certainly something I added decades ago.

so if that is the pin in question leave it unpopulated w/ a manual trans

[drola]

Thanks Bill !!
That's what I'll do. Just pull that pin out of the X4/2 connector and call it done.
Motor should be going back in car in the next day or two