I know there have been several discussions on 4wd not working but I still have a couple of questions. My 4wd has not been working and I have put on a new tcm, and tccm, still nothing. I have no light indicator on my 4wd buttons. I also noticed that I did not have a service 4wd light on my dash. (until tonight). I got to checking all my fuses and noticed my 20 amp atc fuse was blown. I replaced and got my service 4wd light to come on. Then after shutting of the blazer and restarting the fuse blew again. I know this may be a dumb question but what is the atc fuse and why would it keep blowing. I have checked the pins on my tccm connector and noticed corrosin on a couple of them. Would this cause the problem?

 

did you check your grounds. if its blowing that fuse there is gonna be a short somewhere. check and see your wires dont have any insulation missing. start there first.

 

Well after messing with it a little more I have some different results. I replaced the fuse. Unplugged and plugged the wire harnesses back into the tccm and started the truck. Now I have no service light but I do now have the idicator light on my 4wd buttons. The only problem now is when I try to put into 4wd the light just keeps flashing. I hit 2wd and hear the click and the button stays solid. Still thinking I might have a bad connections somewhere.

 

so you now have indicator lights right. did you try 4lo and do you have auto 4wd

 

Yes I now have the indicator lights. When I try auto 4wd the same thing happens as 4 hi. Lights just blink and never go in. When I try 4 lo the 2 hi light stays solid and the 4 lo buttons just blinks. I also notice that when I hit the 4 hi button the lights in my truck dim for a little bit.

 

yea mine dims also but it works. i dont know why the lights dim mines has done it forever. when my 4wd would not work and it had the same symptoms as yours there is a motor underneath that controls the 4hi,4lo, and the auto 4wd it is what makes it switch between the 3 plus 2hi. bad news is there expensive. a used one cost me around 300. i'll look around and see if i can get the part number for you might want to get a second opion also before you hit the wallet

 

http://www.monsterautoparts.com/CHEV...ransfer_ca.htm

that should get you a part number i'd look around somemore if i was you that price seems good but i've have never bought from that site. it sounds to me like the actuator/motor is bad. let me know if it works out

 

The guy I bought the blazer from thought it was the transfer case motor and already had it off. That was the first thing I tried. I bought a used one that the guy said came off of one with 76,000 miles. I was just taking his word of course that it worked. I will still check all my connections first. If I don't get anywhere I talked to a guy that will check the codes for $35.

 

do you have an autozone or similar parts store near you because alot of them read codes for free

 

Wow. I almost have a feeling of excitement. I got 4 hi and auto 4wd to work. Now 4 lo is a different story. Still get the blinking light. I here the relay click, the blazer acts like it want to go in, then goes back to 4 hi. The last time it did the same thing only all the indicator lights went out and the service 4wd light came on. Shut the blazer off and turned back on and 4 hi and auto 4wheel still work?