View Full Version : One more 4.0L swap question
12-07-2007, 09:25 AM
My 4.0L finally runs!!!:clapping: I just have one quick question regarding the transmission. I kept my factory A4LD out of my 88 B2 (I know, it's not recommended) but my question is regarding the overdrive. I have heard that I have to take a green wire from the donor vehicle and splice it into my brake wire so the tranny knows when to come out of overdrive. Has anyone heard anything about this or is this necessary?? My donor was a 1994 Explorer with a A4LD also.
12-07-2007, 12:30 PM
BOO (Brake On-Off) should already be wired to your computer and it's the COMPUTER
that controls the Overdrive via VSS sensor and TPS inputs.
What the BOO triggers is TCC (torque converter Control)
BUT if your auto is the original one to your project that SHOULD already be connected.
Don't go cross circuiting things until you lknow you have a problem.
BTW, when you are ready for the conversion to a Mazda 5sp give me a shout, my brother lives in Wyoming and I live in PA, so for some odd reason I find myself driving across Nebraska from time to time:)
12-07-2007, 03:02 PM
Sounds good. I would have drove it last night to see if that was necessary but we just got hit with a huge snowstorm and with the roads being all iced over I wouldn't be going fast enough to even get the tranny to shift to overdrive. I appreciate the help and will definetly let you know when I decide to do the 5-speed conversion.
12-07-2007, 06:18 PM
So what was wrong in your wiring?
12-09-2007, 05:09 PM
Unless I'm mistaken, he somehow missed the Main EEC ground at the battery.
12-12-2007, 12:17 PM
Yep, I did miss that ground. The plug was cut off very closely to the main harness so I never saw it. After doing some digging I came up with the exposed wires. It started right up after they were hooked back up. That is why they always say: Grounds, grounds grounds!:woot:
12-18-2007, 04:39 PM
I wanted to let everyone know that my 4.0 runs!:yahoo: I drove it home Sunday and there is no turning back. And wow, is it ever the wake up call. No more downshifting on those dang hilly roads around here. I can actually accelerate going up them in overdrive. If anyone is planning on doing the swap in the future and has any questions or problems just let me know. I think I hit every wall imaginable. Now if I could only figure out how to get the 4x4 to work.:icon_confused:
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