Great site, read through all the great articles concerning 4wd and think it might be the cause of fuse 15 (4wd) to blow after less than a mile driving down the road. Just need some direction from the experts here since I've already invested 100 and still haven't resolved the problem. It started with my daughter explaining that her battery light and fuel gauge quit working, so I replaced the belt and tensioner pully thinking it wasn't charging the battery. Then of course that didn't do anything but I noticed the 4wd lights weren't working, so replaced the fuse and thought great, $1 to fix the problem. But as I was test driving it, it sounds like after a short distance that 4wd had kicked it, but when I looked at the 4wd switch, all lights were out. So I replaced the switch thinking it might be the problem, but again, after less than a mile you can hear the 4wd engaged, although the hubs aren't locked in, so I'm not in true 4wd but sounds like it. So when I hear it in 4wd the 2wd switch light goes out, but the fuel gauge and batter light are fine, until the car is turned off. Then when you start the car again the batter light and fuel gauge doesn't work along with no 4wd switch lights.

So any directions will be greatly appreciated. Again, great forum

 

Could the vacuum switch cause 4wd to engage, thus overloading the control motor and blowing the 4wd fuse? Just looking for ideas here before replacing $35 to $150 switches.

UPDATE: Unpluged the vacuum line to the actuator, replaced the fuse and so far two days without blowing the fuse. So I'm thinking either actuator or t-case switch, probably t-case switch since that will be a pain to get to and replace. I'm thinking the t-case switch is bad causing vacuum to actuator thus trying to put it into 4wd, throwing off the encoder motor, thus causing the fuse to blow.

 

Two weeks and counting without blowing fuse 15. So safe to assume it is the vacuum switch on the T-Case. Looks like Advance Auto has one for $17, probably should replace vacuum lines while I'm under there.

 

I thought the 4wd fuse was a 10? It is at least on my 99. I've got the Auto4wd as well though..hmm

 

My 98 Jimmy 4Dr 4x4 is having the exact problem. What happend when you replaced the t-case switch?

 

That thread is old as Mosses with no come back on solution, hate when people do that. You should probably start your own.

Props on obviously doing your own search to start with tho.

 

Thanks I will.