WannaBeGearHead

I am currently swapping in a 4r70w. I have everything basically done and installed except I am having a hard time wiring up the 4r70w tranny harness to my existing T45 setup. The harness for the auto is different then the T45. I have wires that came down and plugged into my T45 but those aren't the same as the 4r70w plug ins.

Any help such as wiring diagrams or where I need to plug the 4r70w harness into would be much appreciated.

cliffyk

Here's the overview and details--you're going to have to get a "donor" harness as there's a whole lot of wires that go straight back to the PCM that likely won't be there on your car...

WannaBeGearHead

Are you talking donor engine harness or donor trans harness?

cliffyk

At the risk of being "curmudgeonly" (my wife accuses me of this all the time), why would I be talking about an engine harness in a discussion concerning automatic transmissions?

devongarver

LOL^^

WannaBeGearHead

I thought the wires going down to my tranny were coming from my engine harness. Still learning about this wiring stuff so please excuse any of my stupid questions.

A guy who has done the swap said he plugged a wire into some place up by the fenderwell, like underneath the air intake filter. Do you know what he would be talking about? Cause the trans harness is very long on the side that goes up toward the engine bay.

cliffyk

Here's a PDF showing an overview of the various wiring harnesses.

The engine has several harnesses for it's various components, the transmission harness (#15 in the schematic) is a breakout of the engine control sensor and fuel charge harness (#16). Distinct part numbers are shown for the manual and auto tranny harnesses, however I see no other distinctions.

Here are both the 3650 and 4R70W connection diagrams.

Both harnesses plug in to connector C1148. This leads me to believe that all you will need is the actual transmission harness.

One remaining issue is that you will have to have the tune's Trans Load Switch and Trans Type Switch scalar values set to 1 so the PCM knows you have a slushbox...

WannaBeGearHead

Thanks Cliff for those links. I will try and see what I can do this weekend. Do you happen to know where you plug in the C1148 and C1168 plugs? Those are the two plugs on the auto trans harness that I need help with but in the diagram it doesn't show where they go. I will have to go out and find out where those 2 plugs are now on my car to see if I can't find where they lead to.

cliffyk

They are inline connectors, so they will connect to a harness somewhere in the vicinity of where they are shown in the diagram...

WannaBeGearHead

Ya I think I found the C1148 plug in. Unfortunately, it is above the top 2 bellhousing bolts which is too high for my arms and when I try to go from the top of the engine bay it is too low. So I'm going to have to a find a person with long, skinny arms lol