Engine/Transmission (1998.5 - 2002) 4 x 4 indicator light

[BSeyler]

Does the PCM, at some point, control the 4 x 4 indicator light on the dash? My indicator light quit working a year or so ago. I haven't been too worried about it since the front end still engages, but would like to get this fixed. I had the dash out one day a few weeks ago and checked the bulb. It was fine, but I went ahead and traded it with the O/D off light - O/D off still cycles on and off at start up, but no 4 x 4 light. I can't remember if it's supposed to cycle or not. I've been waiting for a snowy day to look into this more and today qualified. I checked continuity on the switch on the CAD when engaged and it seems to be okay. I also checked for power coming in at the plug (unplugged) and have 12V - put a jumper wire across it, but still no light on dash. Reattached plug and have juice on both sides. Still no light. Not sure where to go with this. It would be easy to install a different light for an indicator, but I'd rather keep the original in the dash.



Bud

 

[JesseJ]

Same thing happened to me, all the same problems. Swapped the bulb in the dash, replaced the indicator switch on the axle, no luck. Finally found when I started tracing wiring that there is a weatherpack connector from the axle indicator switch that is hiding up close by the front bumper and a wire corroded and finally broke. Couldn't see it until it broke. I'd trace the wires and start looking very carefully at the wiring on the way up from the axle. Just my . 02

 

[BSeyler]

JesseJ,

Sounds like a good place to look. I'll take a look at it again when I get a little time. Thanks for the help!

Bud

 

[SSolderitch]

I found a broken wire wile replacing a bad frame plug talk about above. I think it was caused by a leveling kit. I decided to replace the plug. With a junkyard run, I found the same one used by a chrysler/dodge car, it was back by the left taillight area. I also wanted to extend the wires 3 to 4", so armed with a soldering iron and heat shrink, went to splice in the new junkyard plug. When I went to strip the wire by trying to pull off about 3/8" of insulation when 3" of wire came right off with the strip. Yes I just found a break in the wire. It was right after the tee in the harness, inside the split plastic tubing, directly under the radiator. Hope this helps.

 

[JMcCoy]

I know you said you ran a jumper accross the wires entering the switch, but I would take a second look. When my CAD started to go bad, It did the same thing. The vaccume diaghram had water in it, so it didn't fully engage the axles. As time want on, the CAD stopped working all together (bad day). I eventually went to the Posi-Loc cable CAD system. To test it, just pull the CAD off and push the button by hand. GOOD LUCK.

 

[BSeyler]

Thanks for the replies. I really think it is an electrical problem somewhere up the line. I have power coming in to the switch. I pulled the plug apart under the radiator and it's the same there - power coming down, but no light when a jumper wire is attached, so I will move on up the circuit looking for a problem. I removed the switch from the CAD and there is continuity when it is depressed by hand. It also has continuity when installed and 4x4 is engaged. I'm going to remove the CAD today to make sure it is fully engaged.

I like the Posi-Loc concept and plan to upgrade at some point this spring. I'm just not totally confident with vacuum and electrically operated systems. I've kicked around the idea of adding the two low kit because backing with a heavy trailer is much easier in low range. But, the Posi-Loc really looks like the way to go - two low and definite axle engagement.

Sidenote: I really know how to spell gauge. I've tried to get it right in my profile and it keeps coming up guage. When I look at my user profile, it's spelled right. Gremlins, maybe?

 

[BSeyler]

Finally got some time to find and fix my problem. It turned out to be the plug under the radiator. One wire inside had deteriorated - it's working now. I took the switch out and measured the travel on the vacuum actuator. Then, took the CAD cover off and compared to make sure it is engaging fully, which it is. I still like the looks of the Posi-loc and will upgrade when I get another shop day.