oddballracing

Hi All,

I've got a 95 ZJ, 4.0/42RE/NP231 that has recently developed a failure to display 4WD position. I have tested the wiring by jumping the terminals on the harness (ground terminal to the 3 circuits that light up the GDM. All three of the switched grounds appear to be fine, i see the appropriate 4 wheels, part-time and full-time (unused with the 231) lights illuminate at the appropriate points in the test, testing the switch on the bench also gives me high resistance between the points while depressing the plunger on the switch to various depths, cannot get consistent continuity on any of the circuits at any point. The problem is that i cannot find an electric 4-pin switch other than the longer 242/249 switch. As this is the first time i have ever pulled one of these, I compared this with my 98 (with a NP242) and the threads on the 231 switch (and in turn the overall depth into the case) is about half the length of the 242 switch, despite many sources on the internet stating they are the same. The only listed electrical (not vacuum) switch i can find that is the right length is a 2-pin unit, which i suspect is for vehicles that light a single circuit to display 4x4 or not.

Has anyone else seen this? Nothing in the shop manual (genuine Chrysler shop manual) shows any reference to a vacuum switch (no front hub actuator on this rig) or a 2-pin switch, and only shows the same circuit for all three transfer case options (231/242/249) all using the same 4 wires in the diagram that feed the GDM. I will take pictures when i am back at the shop in the morning, but I'm wondering if I've got some weird specimen that parts are not available for.

Any help is appreciated.

Cheers.

oddballracing

Sensors

Connector

Work week was a bit of a nightmare, late with the photos.

The NP231 tag fell off the case when i touched it to wipe it off, but the Mopar part number (R2098319) listed translates to a NP231 in all searches i have done, as well as i have confirmed the case does have the NP logo cast into the rear half of it. as mentioned earlier, both sensors have the 4-pin conenctor associated with the 4-state wiring of the GDM/VIC. I am wondering if I'm dealing with a unicorn, or is it more likely this specific part was discontinued (I believe the 231 was removed as a build option in either 96 or 97).

Thanks again.

oddballracing

I can confirm I'm not the only one who has seen this. I just saw a picture of the same switch (short threads, long switch rod) on the TJ forums from someone doing a 231 replacement. The short answer i saw was that this allegedly was from a 2001 XJ, but my area has no XJs in that vintage for me to compare with. Even searching Mopar part sites show no reference to this switch and everything points back to the Mopar 56006755 part, which is the longer thread unit for 242/249 or the 4 port vacuum switch. Still hoping to decipher what seems to be Chrysler's best kept secret since the inclusion of the CCD bus.