Harness swap necessary?

[boostcraver]

I am swapping my turbo auto equipped '91 to a 5sp. and am curious if there is any difference in the body harness between the auto and manual equipped models for that year, all other options remaining the same. I am looking for a '91 5sp engine harness and ECU but am not sure if I need to be looking for the other harness(es). Thanks to all for your input

 

[Devin LeBlanc]

You don't even need the engine harness and ECU.. Just bypass the neutral safety switch and hook up the reverse switch in the 5 speed trans to the wiring on the auto trans plugs.. Your good to go

 

[boostcraver]

You don't even need the engine harness and ECU.. Just bypass the neutral safety switch and hook up the reverse switch in the 5 speed trans to the wiring on the auto trans plugs.. Your good to go

Thanks Devin. I have seen this done a few times in person and it is an option to just get the car running. For a long term solution I would rather have the reliability of the proper wiring for the equipment/options that are installed. To restate my query in a different way: would the addition of one trans or the other (R154 vs. A340) all by ITSELF change any of the other wiring/connectors ANY where in the car other than under the hood on the engine harness? Are the dash and cluster harness the same manual/auto? How about the ABS speed sensor connector; different style or the same for either trans? How about between years? I am willing to take the time and spend the money to do it right the first time, and am mostly trying to eliminate any compatibility/reliability issues before they arise. I am also all for using what I have if it is usable without rigging something to "make it" work, i.e. all the connectors already exist on my current harness(es) Thanks.

 

[boostcraver]

Bump. Anyone?

 

[mkiiichip]

Your making a simple tranny swap way more complicated than it needs to be.

Yes, the body and engine harnesses are different from auto to manual.

For a long term solution I would rather have the reliability of the proper wiring for the equipment/options that are installed.

Why do you feel that using an automatic harness, is not reliable on a manual car.
The only unreliable factor, would be the quality of the work swapping safety switches and reverse lights.

 

[bioskyline]

the abs plug is the same on both. i had no issues with running the auto harness with my 5 swap.

 

[boostcraver]

Yes, the body and engine harnesses are different from auto to manual.
Why do you feel that using an automatic harness, is not reliable on a manual car.
The only unreliable factor, would be the quality of the work swapping safety switches and reverse lights.

First, thanks for directly answering my question, chip. I just don't want my car to be like the ones around here that have been swapped, IOW, you lift the hood and have a wiring nightmare. I agree the quality of the work plays a part, and it's for that reason I'm doing it the way I am. I don't know enough about the wiring to do a competent job of it myself and there really is no one else around here that I would be able to completely trust with my car to get it right. In my particular case, this IS the easier route to the intended goal.

---------- Post added at 04:58 PM ---------- Previous post was at 04:56 PM ----------

the abs plug is the same on both. i had no issues with running the auto harness with my 5 swap.

Thanks for that info. Much appreciated.

 

[whitemike]

Your making a simple tranny swap way more complicated than it needs to be.

Yes, the body and engine harnesses are different from auto to manual.

I don't think so, for completeness.. if it matters to him that much..

As someone who's personally converted an auto 7M to a 5spd 7M.. I can tell you that I haven't had one problem with the swap still using the Auto harness AND ECU. I bypassed the neutral safety switch (recommended anyways for your thrust washers' sake) and the only lingering "issue" is my O/D light flashes when I first start the car.

As for reliability.. you're simply not utilizing wires in the harness that the auto tranny needs. The body harness is probably different due to the things in the dash like the O/D light.. not to mention the ECT computer.

Mike

 

[boostcraver]

I don't think so, for completeness.. if it matters to him that much..

As someone who's personally converted an auto 7M to a 5spd 7M.. I can tell you that I haven't had one problem with the swap still using the Auto harness AND ECU. I bypassed the neutral safety switch (recommended anyways for your thrust washers' sake) and the only lingering "issue" is my O/D light flashes when I first start the car.

As for reliability.. you're simply not utilizing wires in the harness that the auto tranny needs. The body harness is probably different due to the things in the dash like the O/D light.. not to mention the ECT computer.

Mike

The first sentence of your reply pretty much sums it up, Mike. It's a details thing. I suppose I could always de-pin and remove the superfluous wiring so It didn't look like a total rats nest under the hood and get it going for now... It would be nice to be able to drive it But ultimately, I do want to eventually get it 100% 5 sp. spec. That way it looks like it came from the factory so equipped.

 

[7Matt-GE]

you might have an entire wiring nightmare just doing the harness swaps. Bypass the Neutral saftey switch and a bunch of cable management and you should be rockin.