dkmcgowan Posted November 30, 2015 Share Posted November 30, 2015 I just finished a swap to convert my automatic (AW4) to a manual (AX15). I got the harness all hooked up to bypass the neutral safety switch and got the reverse lights working. It's a mid 90's AX15 from a Cherokee, I believe 95 maybe, it has the external slave cylinder. I wanted to get the 4wd indicator light working on the dash. When I pulled the dash to install the longer accelerator cable I made sure to put bulbs in the slots for 4wd indicator and up shift indicator. Do I need another harness with a couple connectors on it though to plug somewhere into the dash? I can see the switch on the transmission and can run a cable up to passenger side of engine bay where the TCU connectors are, but I assume I would need to add something to make the light come on? thanks! Link to comment Share on other sites More sharing options...
yxmj Posted November 30, 2015 Share Posted November 30, 2015 The lights would be activated off of the T-case...not the trans...depends on the year of the case...early 90's would probably still have the vac switch...can you better identify the t-case?_ Link to comment Share on other sites More sharing options...
dkmcgowan Posted November 30, 2015 Author Share Posted November 30, 2015 Sorry, your correct, it's the NP231 from an XJ as well... I see the indicator switch and have it run up my custom harness to the passenger side engine bay. I don't think this transfer case has anything for the upshift indicator, I don't see another switch or anything. So I was trying to atleast get the 4wd indicator working. I have read there is some wire that should be in the harness, but haven't found it. Link to comment Share on other sites More sharing options...
yxmj Posted November 30, 2015 Share Posted November 30, 2015 T-case will not have up shift indicator...if it has a vac switch then originally when you pulled back on the 4wd lever that opened the vac switch that caused a vac line to move the CAD fork over and engage your front diff....when this fork moved to engaged it pushed a switch that turned the light on on the dash....again...if it is a 231 with a vac switch..... you could make it work if you had a small vac actuator (like the one on the heater control valve) and a momentary switch......hook the vac line to the actuator so it presses the switch....hook the switch to the light....Does that make any sense? Link to comment Share on other sites More sharing options...
cruiser54 Posted December 1, 2015 Share Posted December 1, 2015 Doesn't the lever on the floor indicate enough for you? Link to comment Share on other sites More sharing options...
dkmcgowan Posted December 1, 2015 Author Share Posted December 1, 2015 The floor indicator is good enough, it isn't a big deal and not spending too much effort to figure it out... I just had the extra wire in the connector on the mid 90's AX15 and no where to plug it in the engine, tracked down what it was, realized my 89 still had the dash indicator, and was just curious if I could hook it up... Link to comment Share on other sites More sharing options...
cruiser54 Posted December 1, 2015 Share Posted December 1, 2015 The floor indicator is good enough, it isn't a big deal and not spending too much effort to figure it out... I just had the extra wire in the connector on the mid 90's AX15 and no where to plug it in the engine, tracked down what it was, realized my 89 still had the dash indicator, and was just curious if I could hook it up... Alright, you're off the hook...... Link to comment Share on other sites More sharing options...
Doc. Posted December 2, 2015 Share Posted December 2, 2015 If I went to all the work of converting to 4wd I'd like to see a light in the dash too. Just because. I have no useful info for you, but hope you get it figured out just the same. Link to comment Share on other sites More sharing options...
yxmj Posted December 2, 2015 Share Posted December 2, 2015 The floor indicator is good enough, it isn't a big deal and not spending too much effort to figure it out... I just had the extra wire in the connector on the mid 90's AX15 and no where to plug it in the engine, tracked down what it was, realized my 89 still had the dash indicator, and was just curious if I could hook it up... Any wire coming off the AX15 would have NOTHING to do with 4WD....an AX15 is a transmission.....your transfer case diverts (transfers) the power to the front axle when it is engaged. The wires that come off of the AX15 (please correct me if I am wrong but I am pretty sure there are only these)....one runs from a ballbearing momentary switch that is in the reverse position (turns on the white lights in your tail lights when you put it in "R")....the other is not an activator but a de-activator....it goes to the same type of ballbearing momentay found in your 5th gear channel....it actually de-activates your shift up light...for those whe seek that elusive 6th gear when the revs get high. Just MHO....pics with questions like this will get you quicker more accurate answers... Link to comment Share on other sites More sharing options...
Pete M Posted December 2, 2015 Share Posted December 2, 2015 pictures of what's on your truck might help out with the confusion. :thumbsup: Link to comment Share on other sites More sharing options...
yxmj Posted December 2, 2015 Share Posted December 2, 2015 Like I said above you could make it work... Google this "SPST vacuum switch" If you can come across a switch like this....or alternatively make one like I said out of a vac actuator and a switch....then it would go like this.....on side of the switch goes to your accessory fuse (one that only goes on when the key is turned on the other side goes to one terminal on the light the other terminal of the light is grounded. The switch on the 231 has 4 outlets....search this site for a drawing of what they are....hook a vac line from your manifold to the 231 switch....hook the 4wd output hole to the SPST vac hole. now when the motor is running and you pull on the 4wd lever the switch on the 231 will open causing a vacuum that will activate the SPST switch and turn on the light..... We will give you a couple of minutes to hook that up and report back . :MJ 1: . Link to comment Share on other sites More sharing options...
Dadinator Posted December 3, 2015 Share Posted December 3, 2015 Did same swap. With non cad front axle. I wondered why light quit working, but didn't really care. ;) Link to comment Share on other sites More sharing options...
cruiser54 Posted December 4, 2015 Share Posted December 4, 2015 Can't imagine how I drove those twin stick transfer cases all those years with no indicator lights. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 4, 2015 Share Posted December 4, 2015 The 4WD light switch on the Renix and early HO models with the vac setup, activates the dash light by grounding out when said switch has vacuum pulled on it (see first image, below). It's located on the passenger side inner fender, right by the blower motor. The later model 4WD switch is on the transfer case, bolted in the same location as the 4-port vacuum line adapter, and has a two prong plug (see second image, below). I have not found the time to do this to mine, but it theory, you should be able to ground one leg of that two prong switch on the later model T-case, and on the other leg, run it to the plug on the harness where the old vacuum activate switch plugs in to. When you place the T-case into 4WD, it should cause the two prong switch to tie to ground, and subsequently ground the dash light to enable it to turn on. Vacuum 4WD (dash light) switch: Two prong 4WD switch (found in later model T-case): Simple diagram of the vacuum Command-Trac system: Link to comment Share on other sites More sharing options...
gogmorgo Posted December 4, 2015 Share Posted December 4, 2015 The wiring harness that came with my '93 non-cad tcase plugged right in to where the cad tcase harness was plugged into my '91 MJ and works perfectly. The connector's at the transmission dipstick tube. If manual trans, I suspect it's in the same spot (towards rear right if head) but I can't confirm that. Can't say that the newer electric switch will be a direct swap for the vacuum switch in the old tcase, though. Link to comment Share on other sites More sharing options...
dkmcgowan Posted December 4, 2015 Author Share Posted December 4, 2015 The 4WD light switch on the Renix and early HO models with the vac setup, activates the dash light by grounding out when said switch has vacuum pulled on it (see first image, below). It's located on the passenger side inner fender, right by the blower motor. The later model 4WD switch is on the transfer case, bolted in the same location as the 4-port vacuum line adapter, and has a two prong plug (see second image, below). I have not found the time to do this to mine, but it theory, you should be able to ground one leg of that two prong switch on the later model T-case, and on the other leg, run it to the plug on the harness where the old vacuum activate switch plugs in to. When you place the T-case into 4WD, it should cause the two prong switch to tie to ground, and subsequently ground the dash light to enable it to turn on. Vacuum 4WD (dash light) switch: Two prong 4WD switch (found in later model T-case): Simple diagram of the vacuum Command-Trac system: Lot's of great info here... This vehicle was not originally 4wd, so that vacuum actuator is not there on passenger fender. I'm curious if the plug is there or not, but I didn't initially see it. If that plug is there pretty sure I could wire it up to the newer t-case connector somehow. I will check and see if plug is there. Thanks! Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 4, 2015 Share Posted December 4, 2015 The plug should be there. I have a 2WD '88 MJ I'm working on now, and I've been fixing the wire harnesses from prior damage, and there was one on it. I'll go compare my '88 XJ (which is 4WD from factory) and take a picture for your reference. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 4, 2015 Share Posted December 4, 2015 Okay, as I mentioned before, the plug should be there on the factory wire harness. It is a female bullet connector with a black (or dark blue, my eyes can't tell) wire with orange tracer. One thing that is interesting to note is that the first one, which is pictured from my 2WD MJ, has a single wire whereas my '88 XJ 4WD has two wires. Not sure why, or what the other wire goes to, but just be aware that your harness may look like either variety. 2WD MJ: 4WD XJ: Link to comment Share on other sites More sharing options...
dkmcgowan Posted December 4, 2015 Author Share Posted December 4, 2015 Great pics, thanks! So if you just ground that, the light should come on? So I just need to find which wire makes a ground in the 2 prong connector on the newer t-case when engaged, put a male connector on it, and should all work. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 4, 2015 Share Posted December 4, 2015 Great pics, thanks! So if you just ground that, the light should come on? So I just need to find which wire makes a ground in the 2 prong connector on the newer t-case when engaged, put a male connector on it, and should all work. Yes, essentially. You'll have to ground one leg of the 2 prong switch and attach the other leg to the aforementioned Black/Orange wire (see sketch, below). That way, when the ball inside that 2 prong switch unites the two legs, it should provide a path to ground, thus allowing the dash light to come on. Please let me know if this works as I theorized so that I may do this to both of my Jeeps. Link to comment Share on other sites More sharing options...
yxmj Posted December 4, 2015 Share Posted December 4, 2015 726 I would guess that the second wire is for the second light...the NP 242 was avalible that year so you had 2 choices for 4 HI....part time (yellow light in my 98) and full time (blue/green light)....just a guess. Link to comment Share on other sites More sharing options...
dkmcgowan Posted December 8, 2015 Author Share Posted December 8, 2015 So this works... My 4wd light is working at this point. I did have one weird issue. So it's an 89 2wd MJ, I added the bulb to the dash indicator, and i did a continuity test between the dash light and the wire over on the passenger fender and it was a connection. I verified the ground from the new NP231 switch, all was good right? The line on the passenger fender that should just need to be grounded to make the light show, was showing like 2V of power??? Strange and wrong... We checked inside the dash, all was good, compared to another MJ, all was correct... So I ended up finding the wire right inside the firewall inside the engine bay and I cut the wire, and ran a new wire to the passenger fender, hooked it up to the 4wd switch, and the light works perfect. Now that the wire is cut, there is no longer 2V on that wire. This makes no sense to me... I had the harness apart at one point to fix the ground wires and all the wires looked good, no damage was visible that I could see. Not sure where it was picking up the voltage, now I'm worried I need to take the harness apart or something. All is working now though. Thoughts? Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 8, 2015 Share Posted December 8, 2015 You lost me on the cutting and re-wiring part. Elaborate? Pictures are appreciated as I'm a much more visually based learner. :thumbsup: Link to comment Share on other sites More sharing options...
dkmcgowan Posted December 8, 2015 Author Share Posted December 8, 2015 I will get pictures tomorrow... Essentially a wire comes from the dash indicator lights, out through the connector into the firewall, and then into the engine bay wiring harness. It ran all the way across the fire wall and a small connector shows up on the passenger side fender to hook up the 4wd dash indicator light. Simply touching that connector to ground should just make the dash light show up, simply as that. The issue was that ground connector for the 4wd dash indicator was showing somewhere around a random 2V of power on it. I didn't think it should have any power on it. So trying to ground it would arc of course, since it had power. So I found the wire coming from the cab, through the electrical connector, out into the engine bay through the firewall. I found which wire was the one for the 4wd indicator light and I cut it, right before it went into the harness. I then ran myself a new wire along the engine harness to the passenger side of the engine and connected it to the 4wd indicator switch on the NP231. The result, the 4WD indicator works just as expected, all is good and great and works. I double check the old wire still hanging there that should have been the factory connector for the 4wd indicator light, that is now cut on one end, no more voltage after it was cut. So now the original 4wd wire for indicator light is a dead wire inside my harness. I just have no idea where it got the voltage from inside the harness. It worried me that something is wrong in my harness. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted December 8, 2015 Share Posted December 8, 2015 Ok, I understand what you did. Great description. :cheers: I don't know why you had 2 volts on the original connector. I will have to measure mine to see if mine does the same. Link to comment Share on other sites More sharing options...
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