Hey, I've got a 99 blazer with the auto 4wd. and i was playing around in our fresh snow saturday for about 4 hours in auto 4wd. and it worked great. i was driveing down a road in the slush and heard a clunk of ice hit the underside sumwhere but didnt think anything of it. when i hit a lil ice i hit 2wd to have sum fun and all my lights wen out on my switch. no power no nothing. i checked underneath and it was packed with snow so i cleared sum away and checked the connections. they were still on and tight. i checked both fuses and the atc fuse was blown. i replaced it after about an hr of wondering what happened. and it clicked and came back to life.. it all worked great again... well. i go to play in a snow drift and on the 4th pass thru i lost 4x4 again. it blew the fuse again. now im thinkin maybe i got a short or its grounding itself sumwhere... i checked my wires and retaped them thinking maybe it got wet too.. and i put it all back together and it worked again with another new fuse... for a wile.. i drove around the country block and right before i turned back home i lost it again.. its all been about 5-8 minutes into it running when it kicks the fuse. i have no more ideas wat it could be.. i bought a new selector switch and put it in. didnt help. could it be the encoder motor? when it gets hot would it just trip it like that? my service 4x4 light has never come on at all.. so im baffled! i've read every treaf i can find on this and nothing seems to work. i cant diagnose it because i dont havea plug in my 13 terminal on my dlc. wat else could my problem be? oh. when i was retaping my wires i noticed a bare wire in the mix. im guessing thats the ground wire right? or did sumthin get hot and melt the sheathing away from a wire? anything will help. im in the dark now. thanks

 

Does this help?
I wonder if your orange power wire has a short to ground?

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Thats the only other thing i thought might be the problem but i didnt have a wireing diagram. im going out to look into the wireing again today. Thanks!

 

ok. so i got to looking at that diagram and mine is differant. my motor has the 6 pin terminal on the encoder. and none of them are orange. so i dont have any idea what on is power. i havea red one. If the encoder motor got too hot would it blow the fuse too? because i tryed it again today and after about 5 minutes of driveing the 2wd light went out and i lost 4x4 again. . i talked to a auto eceltric shop and they said it could be the motor doing it. i works perfectly when i put in a new fuse. but then i blow the ATC fuse after about 5 minutes.

 

There are two connectors for the encoder motor on a two-speed automatic transfer case such as you have (NVG 236).

Attached are the connector views and the additional wiring harness information back to the TCCM (located behind the passenger side kick panel in front of the passenger door).


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ok. a lil new info... i found that set of wires and they look fine. connections strong and clean and dry... i put in a new fuse again... and let it sit there and run for well over 20 minutes and i was shifting it thru all 4x4 ranges the entire time. and it worked flawlessly . so i put it it 2 hi and took it for a drive. i got on the road drove about 200 yards and started to slow at a stop and it went out. so i pulled into a parking lot and shut it off and got underneath and it wasnt hot or anything. so i tryed putting in a new fuse.. it blew INSTANLY! so i drove it home. let it sit for 20 minutes and put in another fuse.. it didnt blow. im soo lost. everyone ive talked to around here in garages dont have any idea y its acting up like that..any body else think it could just be the encoder motor?

 

If it is the motor, disconnect the wiring and drive it around. If it doesn't blow, it's something internal, but I doubt it. Definitely sounds like a wiring issue to me.

 

Ok. ill try that tomorrow. i dont understand why it isnt kickin on the service 4x4 light. Im gonna go out tm and track all of the wires down. and examine all of them. this thing is driveing me crazy!.thanks for the diagrams guys.

 

if i were to cut that orange power wire and run another wire done and splice it into the harness underneath would that bypass any ground shorts? i put in a jumper to test it after it got hot and it worked. and then that orange wire started to smoke for a split second up by the firewall... and it didnt get hot down by the harness underneath. so i think theres a break in the wire up in the harness were i cant get to it. so if i bypassed that power wire it would take care of the ground short right? I've got an appointment next week to have a electric auto shop look at it but if i can figure it out itll save me a mininum of $65/hr!