ParadiseMJ Posted February 27, 2013 Share Posted February 27, 2013 OK, I've never had a transfer case with wires on it. When I swapped the HO AW4 into the Renix truck, I had to get another t-case to mate to the tranny. I replaced the NP231AMC with the NP231J (I think the donor was a 94-96). There's a two wire connector coming off the transmission harness that plugs in to the t-case... What is that and what does it do. Link to comment Share on other sites More sharing options...
Alexia Posted February 27, 2013 Share Posted February 27, 2013 If it is the wire on the front of the case it is for the 4WD sensor light. The one on the rear at the tail shaft is the speed sensor. Link to comment Share on other sites More sharing options...
cruiser54 Posted February 27, 2013 Share Posted February 27, 2013 OK, I've never had a transfer case with wires on it. When I swapped the HO AW4 into the Renix truck, I had to get another t-case to mate to the tranny. I replaced the NP231AMC with the NP231J (I think the donor was a 94-96). There's a two wire connector coming off the transmission harness that plugs in to the t-case... What is that and what does it do. Uh-oh. Someone smarter than me about this stuff needs to chime in. You do have your speed sensor plugged in, right? Link to comment Share on other sites More sharing options...
mvusse Posted February 27, 2013 Share Posted February 27, 2013 231AMC? What vehicle is this in? My 87 Comanche has a 231J from the factory. But as Alexia stated, the transfer cases without the vacuum axle disconnect stuff have an electrical switch to turn the 4wd on/off. Newer 242 case have a three position switch for separate full time and part time lights. 91 and newer also have an electronic speed sensor, but for older electronics the mechanical one fits the same hole. Link to comment Share on other sites More sharing options...
juan Posted February 27, 2013 Share Posted February 27, 2013 you don't need the 4wd light to be on to tell you you are in 4wd - when I swapped my front disco d30 fro a non disco d30 I lost 4wd switch indicator and I have not miss it at all, you do have to hook up the spedo sensor... Link to comment Share on other sites More sharing options...
JFAComanche6 Posted February 27, 2013 Share Posted February 27, 2013 231AMC? What vehicle is this in? My 87 Comanche has a 231J from the factory. But as Alexia stated, the transfer cases without the vacuum axle disconnect stuff have an electrical switch to turn the 4wd on/off. Newer 242 case have a three position switch for separate full time and part time lights. 91 and newer also have an electronic speed sensor, but for older electronics the mechanical one fits the same hole. My NP231 says "231 AMC" on the top of the tag, but I assumed it was the same as a 231J since AMC made Jeep for a while. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted February 27, 2013 Author Share Posted February 27, 2013 If it is the wire on the front of the case it is for the 4WD sensor light. The one on the rear at the tail shaft is the speed sensor. The speed sensor is on the rear of this tranny AFAIK, Kind of looks like a gray plug with a long shaft (2") that slides in to the trans. and a bolt to hold it in. It's got a tan wire which coincides with the tan speed sensor wire in the harness I don't have any wires, vac lines or connectors on or near the tailpiece. Uh-oh. Someone smarter than me about this stuff needs to chime in. You do have your speed sensor plugged in, right? Oh, come on!! There is no one smarter than you IMHO, but AFAIK, yes. This plug is right at the top forward of the speedo. The wiring was hanging down, apparently got snagged by the front shaft and ripped out, which is why I'm even looking at it. Again, everything seems fine as far as driveabilty, in and out of 4x. 231AMC? What vehicle is this in? My 87 Comanche has a 231J from the factory.. The 231AMC was what was in it with the BA/10...maybe it was designed to mate to the Peugot, I dunno, it was stock. My 90 XJ has a 231J and looked identical to the 231AMC, all the same parts, switches etc. But as Alexia stated, the transfer cases without the vacuum axle disconnect stuff have an electrical switch to turn the 4wd on/off. Newer 242 case have a three position switch for separate full time and part time lights. 91 and newer also have an electronic speed sensor, but for older electronics the mechanical one fits the same hole. Also AFAIK the t-case is only engaged (and front axle powered) by linkage. No electronics involved, except for the light. I can't imagine that this little plug (black wire/red tracer and gray/yellow tracer) do much more than turn a light on/off, but I could be wrong. My front axle has the CAD locked over, no vac switch on this T/C and all the vac lines are gone now. And the light does NOT work...but I really don't need it. I was hoping I could somehow wire this in to the vac activated circuit for the light, but not my main priority. I have a mechanical speedo gear, original Renix speedo and cable...I do need to swap out the gear for the right one since I'm running 31's. The speedo is about 12% off according to my GPS and highway mile markers. Also low priority for me since it is not my DD. you don't need the 4wd light to be on to tell you you are in 4wd - when I swapped my front disco d30 fro a non disco d30 I lost 4wd switch indicator and I have not miss it at all, you do have to hook up the spedo sensor... As mentioned above...I'm not really too concerned about the light. It'd be nice but not super important to me. Thanks for the replies gents. Looks like I'm looking at speed sensor (although I'm pretty sure that's taken care of) or the wiring just for the light. I now will dive into the franken-Jeep wiring diagrams. Arrgghh! Link to comment Share on other sites More sharing options...
cruiser54 Posted February 28, 2013 Share Posted February 28, 2013 Mighta figured it out... The 231J, which I have in my 90 MJ only has a vacuum switch on the transfer case at theh rear. There is a speed sensor in the adapter housing between the trans and t-case. There is also a 2 wire harness that goes nowhere on a 231 equipped model. If you add a jumper to it like the factory did, it goes to the electric switch on the t-case for a 242. Black with red, gray with yellow wires. The speed sensor wires are white with brown and black. They run along with 3 other wires for the solenoids. Hope this helps. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted February 28, 2013 Author Share Posted February 28, 2013 Mighta figured it out... The 231J, which I have in my 90 MJ only has a vacuum switch on the transfer case at theh rear. There is a speed sensor in the adapter housing between the trans and t-case. That's what I got. So maybe the tranny that I got is meant to mate up to the 242...I dunno, fellow Jeeper gave it to me with no specs. There is also a 2 wire harness that goes nowhere This is the story of my life Link to comment Share on other sites More sharing options...
cruiser54 Posted February 28, 2013 Share Posted February 28, 2013 I believe that the Jeeps were wired for BOTH the 231 and 242. If you had the 231, the harness dead-ended near the adapter and the vacuum switch was used. If you had a 242, the electrical switch was used with a jumper harness. Link to comment Share on other sites More sharing options...
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