The 4 wheel drive "Engaged" light on my dash has never worked, so I took apart the dash to check the bulb. I found there was no bulb, and even the fixture to hold the bulb had been removed. I figured that wiring in a new fixture and bulb into the dash would be no problem, as long as I could find the right sensor, which I would think would be on the transfer case, and check that it is working properly.

I went under the truck and found only one sensor-type plug, which is on the top of the TC, near the right rear. Using a multi-meter, I checked continuity while in 2WD, and got nothing, as expected. However, when in 4WD, I also got nothing. So, either the sensor is bad, or it's the wrong sensor to be checking, or I wasn't actually in 4WD (my truck is extremely difficult to shift into and out of 4WD).

Does anybody know if I'm checking the correct sensor? Or if it is normal for these to go bad? Or where the right one is, if that isn't it?

Thanks a bunch,
CR

 

That's the one. It's a real cheesy setup, thanks Dodge. I've never had to troubleshoot one on an NP205 and the shift linkage is different from the chain drive cases. The switch is probably toast---could be stuck in/out. Unthread it out of the case and give it a good douse with PB blaster then re-check the continuity. It's pretty obvious how it works once it's out. Good luck and keep us posted!
greg

 

Switch is shot, should be closed in 4wd. Open 2wd & neutral.

 

Hard to shift into 4WD.

You can take off the boot, Place the shifter in 'N', Loosen up the 3 bolts and push the 4wd shifter as far forward as possible (shouldn't be much). Then tighten the bolts back up. Then try shifting.

I have read that in the service manual when I had one. That might help in the alignment of the shifter, else it could be internal to the T-Case