First off, thanks for taking the time to read my post and TIA for any and all replies...
My husband and I just bought a 2000 Blazer (automatic) from our neighbor. Thier daughter (approx 20yrs old) had it and we knew it needed some work under the hood. The body and interior are perfect and we thought, "what tha heck....this will be our project". We only have 1 other vehicle, so fixing this one so we can another reliable truck will help tremendously... So we paid about $900 bucks for the truck...

The 4wd issues are that all the 4wd dash lights are lit up. We've attempted to do disconnect the battery and pull out the atc fuse, both which have failed... Could we be so lucky that this could be just a switch that needs replaced or are we looking more at the TCCM, encoder motor or actuator....??? If it's one of the more expensive is there a way to just unhook the 4wd completely right now until we are ready to fix it? I ask this since we have other "issues" we need to fix first. Can this be done by disconnecting the TCCM by chance? The neighbor's daughter had apparently been pulling the #15 fuse while driving it - however this also causes the fuel gage to not register?? Honestly, I'd rather just disconnect the 4wd completely for the time being....

We changed the oil (which wasn't even registering on the dip stick and was like black sludge), changed the air filter, going to change the gas filter.... Right now when you attempt to start it you 9 times out of 10 have to jump it off first (although the battery is new). I'm assuming the battery isn't holding charge since the vehicle hasn't been driven in a while and when you do get it started, you can't drive it long enough for it to build up and hold charge. (????) The carburetor DEFINITELY needs cleaned I believe as it's black black black inside.... Also black smoke comes from exhaust. (Possibly from carburetor or fuel injectors???) When you do get it started and "attempt" to drive it, it idles rough, has no power, bogs down and will stall when you come to a stop or at times even when you're driving.... She stated that it started the majority of this after "bad gas".... I personally think the vehicle hasn't been maintained at all and possibly if we change the spark plugs, fuel injectors, clean the carburetor along with the oil change and new filters that could possibly do the trick???

So, that pretty much sums everything up. We're definitely not discouraged with the work ahead of us. I think that we can fix our blazer up to be a great vehicle. She definitely needs a little TLC.....something she's apparently lacked. I'm a gal that doesn't mind gettin' greasy, so let me have it....
First, how can we disconnect the 4wd at the moment so it doesn't interfere with the driving performance. (Then what steps should we follow to determine what that problem is.)
And any other ideas of what the other problem is/problems are??

Thanks so much - Deb.

 

Suggest doing a tune-up but use only Delco distributor cap/rotor...forget the cheap ones.
Plugs and wires.
There is no carb on the engine, fuel injection, which sounds like it is running very rich. Mas air flow meter is probably dirty; clean very, very carefully....very small wires/resistors in there.
Probably should remove throttle body and give it a good cleaning as well.
I would not try to drive it much as the rich condition will plug the cat up and then it will need replacing.
I think you can just remove the fuse for 4wd to get the lites off for now. Sounds like either the controller is gone, or there is a wiring problem like a broken wire or bad connection(s).

Suggest getting the engine running first, then tackle the 4wd part.

Good luck with this project.

 

Thanks for the response =)

Correction on my part.... It was the throttle body that we cleaned.... And it was extremely black with build-up.

This is what we've done so far:
Oil Change
New Air Filter
New Gas Filter
Cleaned Throttle Body

This is what we're doing tomorrow (Saturday 8/25):
Replacing Plugs and Wires
Replace fuel injectors
Replace Distributor Cap & Rotor
Clean Catalytic Converter
Locate and Clean Mass Air Flow Meter (Is this the same as the mass air flow sensor??)

Hopefully this will do the trick....

One other quick question though. Is there another way to disengage/disable/unhook the 4wd besides pulling the fuse. Reason being is that when the fuse is out, the fuel gage doesn't normally register. It is possible to just disconnect the TCCM & encoder motor completely? Honestly, 4wd is not something that we "need" so this is not on our priority list to fix or worry about as long as it doesn't get in the way of the trucks performance. Ideas or suggestions??

Thanks again.

 

Is the 4WD engaged when the dash lights are on? Based on your description of the vehicle's maintenance before you bought it, I would guess that the 4WD isn't working at all, but please confirm. If that's the case, don't worry about driving it with the dash lights lit up, unless you hear/feel grinding in the front end. Those problems are often caused by the TCCM and/or transfer case shift motor. Sounds like you have other issues to address first.

 

I have a 99 Blazer 4wd that I have done considerable 4wd diagnostic work and fixing. I would not worry about the dash lights coming if you can verify that it is actually operating in 2wd. If it is in 4wd and you are trying to get it manually into 2wd you can remove the encoder motor which is bolted onto the transfer case. You have to remove the front drive shaft first. Once off you can use a wrench to physically shift gears and I think 2wd is with the **** pointing relatively level but I could be wrong on that. Make sure the plugs on the encoder motor are disconnected and then I believe you can adjust that to match the **** on the transfer case.

I replaced a encoder motor which the shops said was the problem. That did not work although I did one time use a wrench and wiggle the 4wd shifting **** on the transfer case to see if it was stuck. It actually worked for a bit then quit. The dash switch was getting hot and it was replaced but that did not work so since it was getting hot, the only thing plausible making it hot was the transfer case control module which when replaced with a part from GM made everything work well. It would switch from 2wd to auto 4wd but 4Hi or 4lo would kick on the service 4wd light. Probably some relay in the tccm went bad.

I have a dash switch which I think is good that I would send to someone if they wanted it provided shipping was covered. It has Auto 4wd, 2wd, neutral light, 4wd HI, 4wd Lo.

Good luck with fixing up that neglected vehicle.

 

know of no reason why unplugging the TCCM connector would cause any problems.

But do check to ensure that the transfer case is in 2wd before doing so.

Good luck with getting this neglected Blazer back to road worthy.