95 850 Help! Are these two transmissions swappable?

850TurboTurtle · Post by **850TurboTurtle** » 26 Aug 2015, 15:14

So looking at the sensor pix, what gets wired to where from the new tranny to the old car? That's the part that I still can't figure out.

Post by **Ozark Lee** » 26 Aug 2015, 15:27

There is a twisted pair of wires from each wheel sensor up to the ABS module. The left front is the closest but any of them will work. What you do is just splice a pair of wires into the wheel sensor wires and then attach the other end into the wires where the old speed sensor was plugged in. It doesn't care about polarity.

...Lee

850TurboTurtle · Post by **850TurboTurtle** » 26 Aug 2015, 15:32

Ozark Lee wrote:There is a twisted pair of wires from each wheel sensor up to the ABS module. The left front is the closest but any of them will work. What you do is just splice a pair of wires into the wheel sensor wires and then attach the other end into the wires where the old speed sensor was plugged in. It doesn't care about polarity.

...Lee

Thank you Lee. Forgive my ignorance, but are both the rectangular connector on the old tranny and round connector on the newer tranny speed sensors? So I would just splice in parallel from that round pigtail into the two wires of the drivers side abs sensor on the wheel hub?

Post by **Ozark Lee** » 26 Aug 2015, 17:15

As far as sensors go just the RPM sensor (crank position). The rest of the stuff is on the harness along with the PNP switch.

...Lee

Post by **tryingbe** » 26 Aug 2015, 18:46

Whatever wires going into this, are the wires you want to send the abs signal to.

Leave this plug alone.

850TurboTurtle · Post by **850TurboTurtle** » 27 Aug 2015, 01:31

"just splice a pair of wires into the wheel sensor wires and then attach the other end into the wires where the old speed sensor was plugged in. It doesn't care about polarity."

So, [once reassembled] there will be a rectangular connector hanging off the back of the new tranny to where the old one had a rectangular hole with 2 post connectors, which was the speed sensor for the old tranny. I splice from the ABS sensor wires to the old wire hanging down [which now has nothing to plug in to on the newer tranny], correct?

And the small round RPM crank sensor on top of the new tranny has nothing to plug in to on the wiring harness, so it hangs limp, correct?
Thanks.

Post by **tryingbe** » 27 Aug 2015, 06:38

850TurboTurtle wrote:"just splice a pair of wires into the wheel sensor wires and then attach the other end into the wires where the old speed sensor was plugged in. It doesn't care about polarity."

So, [once reassembled] there will be a rectangular connector hanging off the back of the new tranny to where the old one had a rectangular hole with 2 post connectors, which was the speed sensor for the old tranny. I splice from the ABS sensor wires to the old wire hanging down [which now has nothing to plug in to on the newer tranny], correct?

And the small round RPM crank sensor on top of the new tranny has nothing to plug in to on the wiring harness, so it hangs limp, correct?
Thanks.

Did you miss these pictures and description?

tryingbe wrote:Whatever wires going into this, are the wires you want to send the abs signal to.

Leave this plug alone.

850TurboTurtle · Post by **850TurboTurtle** » 27 Aug 2015, 11:28

Um, yes, in fact - I did miss those! Even I could make sense of it based on the descriptions.

New rule: never check forum late late at night...
Or at least, refresh browser window before posting.

Thanks all.

850TurboTurtle · Post by **850TurboTurtle** » 21 Sep 2015, 14:52

tryingbe wrote:Whatever wires going into this, are the wires you want to send the abs signal to.

UPDATE
After finishing the swap, reassembly, and repairing an intake mani leak, the car is up and running. However, I get A1 code of 2-3-2 speedo signal missing, and A3 code 3-1-1- Tranny RPM signal missing. So something went wrong with the wiring.

What I did was take two wires from the driver's side speedo sensor, and splice each in in parallel, running them to the wires coming from the plug which went in to the back of the old tranny near the pax axle. I heard there was no need for polarity, so I just took a 50/50 chance and soldered them in. So currently the speedy sensor and the plug which used to connect behind the tranny are wired together in parallel.

Should I try changing polarity, or is there some other likely cause? Here is the link to a new post on this particular situation: https://www.matthewsvolvosite.com/forums ... =1&t=72035

850TurboTurtle · Post by **850TurboTurtle** » 22 Sep 2015, 17:10

Ozark Lee wrote:just splice a pair of wires into the wheel sensor wires and then attach the other end into the wires where the old speed sensor was plugged in. It doesn't care about polarity.

Guess what: It does care about polarity!

For whatever reasons, when I did the above splice at first my ABS light came on and the tranny went into limp mode. I had a tranny speedo missing signal code, and an ABS speedo missing signal code. I swapped the wires at the wheel well sensor side and reinstalled and got back my speedo and no more tranny or ABS error lights. So at least on my model it does care about polarity -- in case anyone else gets into this situation.

And no, I have no idea which wires go to which. I took a 50/50 chance and got it wrong first time, and it only requires removing one wheel to access the solder point, so it's not a big deal to know. If you don't have speedo after installing, and get error codes, just reverse the wires at the wheel and presto!