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'87 BA10/5 to AW-4 auto question


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[ba10/5 to aw4 swap

you will need;

 

trans (1987-mid 1990 for or you will need transfercase as well due to spline count changes)

bellhousing

torque converter

fled plate

dust shields

transmission wiring harness (this is seperate from the body harness and the connectors are already there)

engine computer (though this is debatable...some have not had to swap the ECM)

Throttle/trans cable (TV cable) and throttle body mount. the cable is part of the trans, so the only thing you'd need to locate is the mount if you do get the transmission.

TPS the throttle position sensors are also different

TCU (tranny control unit...transmission computer. located under the knee board on the passenger side of the dash. tranny wiring also runs in that location, and you can trail it back to remove it).

pedal assembly with brake switchshifter

shifter plate (plugs the 5 speed shifter hole)

shifter cable and transmission bracket. these are different depending on if the donor has a floor shifter or column shifter.

steering column. you can get by without it, but there is a safety ignition lockout that will keep you from being able to remove the key until it is in park. I run auto columns in my jeeps and bypass the safety feature for the simple fact that the shifter is always put where it belongs, and I don't want any extra crap to break.

 

In my Mj it does not appear to be a seperate harness... I don't see the connectors to plug in the AW4 plugs. It appears to all be part of the body harness on the 88 XJ I'm using as a donor. Any help? Do i really need to swap the whole Harness? :doh:

 

 

I will have to correct myself. The transmission harness is part of the engine bay harness...NOT part of the dash harness. the tranny computer harness is also part of the engine bay harness. it enters the firewall on the passenger side behind and to the pass. side to the rear of the engine. the TCU is located under the knee board.

 

 

to do an aw4 TO 5 speed swap, you do not need to replace the harness...you can splice the trans harness connectors together, and swap the ECU and remove the TCU.

 

however, you cannot do a 5 speed TO auto swap without swapping the entire engine harness, or doing some heavy duty wiring to install wires that simply don't exist in the 5 speed harness.

 

 

So if I am reading this you need the entire engine harness to switch from a BA10/5 manual trans to a AW-4 auto trans? If so what donor should I go with? Am I stuck with '87-'90 XJ's and MJ's? Or can I use parts up to say 1998? I thought the TCU was a stand alone harness and didn't have to be wired into the factory engine harness. I am looking for a donor automatic XJ so these questions are very important.

 

Help please??

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however, you cannot do a 5 speed TO auto swap without swapping the entire engine harness, or doing some heavy duty wiring to install wires that simply don't exist in the 5 speed harness.

 

So with this message I DO have to change the whole engine wire harness?? Is the engine harness for the manual lacking the connectors for the auto transmission harness?? I would rather not change the harness because I feel mine is in good shape and a donor may not.

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I tried to remove one of the AW4 harnesses before and realized the hard way about that. You will need to swap the entire underhood wiring harness from an AW4 equipped Cherokee/Comanche as it ties into a ton of other circuits. You will also need the ECU, too.

 

The wiring changed when the 4.0L went to HO. The most obvious change is that the ECU was moved from under the dasn to on on the drivers side from apron, right next to the air box. If you choose to swap in the HO harness, you will need the entire engine harness and dash harness (as stated earlier).

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  • 4 years later...

I am not going with an HO post '91 swap, I'm asking if I have to change the engine wire harness if I go with the '87-'90 donor.

 

 

 

 

 

[ba10/5 to aw4 swap

you will need;

 

trans (1987-mid 1990 for or you will need transfercase as well due to spline count changes)

bellhousing

torque converter

fled plate

dust shields

transmission wiring harness (this is seperate from the body harness and the connectors are already there)

engine computer (though this is debatable...some have not had to swap the ECM)

Throttle/trans cable (TV cable) and throttle body mount. the cable is part of the trans, so the only thing you'd need to locate is the mount if you do get the transmission.

TPS the throttle position sensors are also different

TCU (tranny control unit...transmission computer. located under the knee board on the passenger side of the dash. tranny wiring also runs in that location, and you can trail it back to remove it).

pedal assembly with brake switchshifter

shifter plate (plugs the 5 speed shifter hole)

shifter cable and transmission bracket. these are different depending on if the donor has a floor shifter or column shifter.

steering column. you can get by without it, but there is a safety ignition lockout that will keep you from being able to remove the key until it is in park. I run auto columns in my jeeps and bypass the safety feature for the simple fact that the shifter is always put where it belongs, and I don't want any extra crap to break.

In my Mj it does not appear to be a seperate harness... I don't see the connectors to plug in the AW4 plugs. It appears to all be part of the body harness on the 88 XJ I'm using as a donor. Any help? Do i really need to swap the whole Harness? :doh:

 

I will have to correct myself. The transmission harness is part of the engine bay harness...NOT part of the dash harness. the tranny computer harness is also part of the engine bay harness. it enters the firewall on the passenger side behind and to the pass. side to the rear of the engine. the TCU is located under the knee board.

 

 

to do an aw4 TO 5 speed swap, you do not need to replace the harness...you can splice the trans harness connectors together, and swap the ECU and remove the TCU.

 

however, you cannot do a 5 speed TO auto swap without swapping the entire engine harness, or doing some heavy duty wiring to install wires that simply don't exist in the 5 speed harness.

 

So if I am reading this you need the entire engine harness to switch from a BA10/5 manual trans to a AW-4 auto trans? If so what donor should I go with? Am I stuck with '87-'90 XJ's and MJ's? Or can I use parts up to say 1998? I thought the TCU was a stand alone harness and didn't have to be wired into the factory engine harness. I am looking for a donor automatic XJ so these questions are very important.

 

Help please??

 

How did you end up doing this?  I have an '88 with the BA10 and I want to swap in an AW4 from the same year or earlier.  Is it as difficult as I'm reading?

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