On my truck my 4wd light stays on no matter what, and my 4wd is not working? Any ideas what would cause it and cause the light to stay on? Dont know if this is a clue or anything but I read on another post someone said this, that my A/C and heater both only blow out of the vents onto the windshield? And mine is doing the same. Any help would be greatly appreciated.

 

Hey, mine does that too. Actually, it goes out sometimes... like the whole time my 4wd was actually on plowing snow for the last two days. But it's usually on.
Regardless...

*subscribed*

 

You have a vacum leak probably a plastic line thats broke

 

Oh yeah, agreed. I was responding only to the 4wd light being on. Since my 4wd works, I'm thinking he has three separate problems.

 

is the 4wd manual or electric ?

 

I've never seen an electric 4wd on a 12V?

 

The "CAD" (central axle disconnect) on the front axle is vacuum-actuated. It moves a little collar across the gap between the diff-side of the right-front axle-shaft, bridging the gap over to the wheel-side. That sends power over there to that wheel. At the same time, the pushing mechanism also closes the little switch, mounted right on the CAD, that sends current to the 4WD light. If the switch is broken, in the "on" position, the 4WD light won't go out. As for the front axle not engaging, AND the HVAC control only blowing in the defogger vent, that's a positive diagnosis of a vacuum leak, somewhere. If you replace all the vacuum lines, (simple, but, tedious and requires a bit of dexterity) you can solve the mechanical problems for about another 6-8 years. Replace the switch, too. OR..... cap off the vac line and replace your vacuum-actuated CAD with a push-pull cable setup. Posi-Loc has several models. I installed one on mine, and have been pretty damn happy with it.

 

Not exactly what I meant by electric, but it does answer the questions. Thanks!

 

Wow thanks. So you think I could replace the actuator and all the vacuum lines and that fix it?

 

The actuator itself is reasonably reliable. If you want to go $25 and functional now, vac lines will probably accomplish that. The posi-loc actually is a remove/replace with a big **** under the dashboard (think of a big choke **** from the old days). That's more expensive, but, as the name suggests "positive". Your electric switch for the indicater light might still be in need of replacement, though