I did an oil change yesterday and decided I would drive a little in the backyard in 4x4 just to keep everything lubed and functioning. Well, if I put in 4H and 4L I noticed I didn't have any kind of dash light to inform me it was actually in 4x4. Now in 4L I could feel the gearing change so I'm confident the transfer case is fine but need help figuring out the dash light. What tells the dash to turn on the light? All other lights on the dash work so I'm sure the light is fine.

Thanks,
Kevo

 

Could be 2 things:
1. The bulb is bad. Pull the cluster and replace.
2. There should be a plunger that's operated by the t-case lever that activates the ground for the light. Check that out.

 

Ckeck the connector on top of the t-case.

 

I'd check the connection on the tcase, going to try and google a schematic.

 

Not to get too much off topic on the original posters subject, but why is it on our cherokees, that when we do put it in 4 wheel drive and our indicator in the cluster is working, there is nothing that says 4 low? I found that a little strange coming from a newer TJ to a 99 XJ. Mine just says part time 4 wheel drive in 4 hi or low.

 

The NP231 has a switch on the TC that makes a ground for the instrument cluster 4WD lamp when 4WD is selected. The lamp is powered by fuse #9 in the junction block but it also powers lots of other circuits so I don't think this fuse is blown.

You can detach the harness connector from the switch and jumper the two pin cavities in the connector and turn your key to RUN. The lamp should iluminate. If not, the ground may be bad (corroded), or the lamp is inop.

The ground point for the TC switch is located at one of the ground studs just below your ignition coil (G101). See pic below.

You can check continuity of the ground with with an Ohmmeter by going from pin cavity "B" on the connector to chassis ground. You should read continuity.

You can check for power to the switch using a Voltmeter by turning the key to RUN and checking pin cavity "A" of the connector to chassis ground. You should read battery voltage.

You can check the switch by placing the TC in 4WD and using an Ohmmeter read from pin "A" to "B". You should read continuity.

 

Thanks for the help, all check all the above and see what happens.