"full time" light randomly coming on

[dkmcgowan]

I have an 89 Comanche that was originally 2wd and an automatic.  I swapped it out to an AX15 with an NP231.  When I did this swap, I found the wire on the passenger fender for the "Part Time" 4wd light.  It looks like 2 wires coming into a single butt connector.  I ran the switch from my NP231, two wires, one wire to ground and the other wire to that butt connector.  Now my 4wd light works perfect, if I shift into 4wd I get the "Part Time" light on the dash.

 

All was great...

 

Now when driving around, if I hit bumps, or just randomly, the "Full Time" light started coming on.  If I stop and push in the parking brake, and then release it to let it slam upwards, it usually makes it go off for a short time.

 

I probably added the bulb to it when I added the bulb for "Part Time", so originally it probably had no bulb.

 

It's my understanding the Comanche never came with a full time case, but the wiring must have it wired for it.  The transfer case that had part and full time had a 3 wire switch on it.

 

How do you think this started coming on?  Where is the wire for the "Full Time", I don't see any other wires over near where the "Part Time" wire was.  I was also always curious why the "Part Time" wire had 2 wires going into the butt connector, is that something?

 

I know I can just take out dash and remove bulb, but now I'm curious how it's shorting to ground and coming on.

[Wiggilez]

I don't know if any mj got the 242 (full time) case but the xjs did, and the xj and mj share a dash a gauges. So it could be possible that thw wiring is there just unused?

[gogmorgo]

The way the 4x4 lights (both of them) work is that the lights have constant power, and the grounds are switched. So you likely have a short somewhere.

On my '91 aw4/231, the wires are part of the transmission solenoid harness.

The white one in this pic:

 

Looks like this on the inside. The two lights for the 242 are the pair opposite the single one.

 

Here's the wiring diagram portion on the 4x4 light, if you can figure it out.

[dkmcgowan]

I figured it must be a short of some kind, or something wrong with the dash indicator itself.  It is grounding somewhere.

 

I think things are pretty different on your 91, I have an 89 Renix.

 

The part time 4wd light is on the passenger fender, I have it circled in red.  I can verify this works and is hooked up to my NP231.  When the full time light was on today, I popped the hood and unplugged the part time light connector in the picture and the full time light stayed on.  Does anyone know which wire is used for the full time light on the renix years?  There are 2 wires on the plug going into harness for the part time light.