I bought this from a lot that I knew better than to buy from, but after driving it and having my step father in law look it over, we decided it was good to go. Well, once we got them down off the $4000 price a bit. It was a perfect day when I drove it, so I didn't run the heat or air very long, although I probably should have. Here's a list of all problems. Keep in mind that I am poor and pretty well car stupid.

-Hi 4 wheel drive went out about 2 weeks after I bought it. Lo still works fine.
-A/C didn't work, put refrigerant in it as it was empty, worked well for less than a week. Back to blowing out hot air.
-Heat don't work. Haven't put a new thermostat in it yet, but that may not be the cause.
-Power mirrors don't want to work, but I don't care too much about that.
-Rear window washer doesn't work, but I'm not too worried about that either.
-You turn the heat to the floor and it comes out the defrost. I've read a bit about that and it seems pretty cheap to fix, but I don't know if I want to fool with it.
-The main thing is the airbag light wanting to come on. It doesn't do it all the time, and sometimes it doesn't stay on for longer than 2 seconds. I hear a GM dealer would have to pull the codes on that, and lucky (and I say that with sarcasm) for me it was the local GM dealer that sold me the Blazer. I've not heard anything good about the dealer, and even less good about their service department.

It gets hot here and I can't put the 2 babies in something with no air, so I've got to get that fixed ASAP. Air bag light worries quite a bit too. Some people might say the lot got me, however I traded them a car that I would've just junked anyway as it is only worth the $10 of gas that was in it's tank. Any help on these problems would be appreciated.

 

Thermostats are designed to fail "open". This way if it does fail, it will still allow coolant to circulate through the system instead of the car over-heating. With that being said, you should get "heat" but what happens is that it takes quite a bit longer for the coolant & engine to warm-up because it is constantly circulating.

Next time you are out for a decent length ride (probably 20+ mins), keep an eye on your temperature gauge. When it hits around 200 degrees and stops rising you should have heat. If you don't, then you have a different problem. Could be that the heater core is bad, the blend door is not functioning properly, etc.

 

Yeah, I hear the 98 Blazers have a lot of problems with the heater core. I don't smell antifreeze or anything, someone told me I'd smell it if it was the heater core, but the 2 hoses have been at different temps before. It has the dexcool in it still, i may have that flushed and changed this week to see if that helps. Too cold to mess with anything outside today though . I've left it in idle for a half hour or so before and went into a warm truck. Even today it was putting out a little heat until I hit the highway. Thanks for the help.

 

1- Your 4HI problem is likely the encoder motor on the side of the transfer case, but it is possible for the switch to be bad. If you only have a 3-button switch, you can check out the Tech Article (DIY) section the OBD2 Non-Automatic Transfer Case Diagnostics thread as well as 4x4 No Worky.... Maybe this will help.... & NV233 transfer case / encoding motor switch

2- This pretty much confirms that you have a leak in the system. You can get some replacement refrigerant that has stop leak in it, but this can clog the orifice tube. Most replacement refrigerant has a leak detecting dye in it which glows under a black light.

3- The likely cause is a plugged heater core. A core does not have to leak to cause heating issues.

4- Could be weak motors or a switch problem.

5- Is this a problem with the wiper itself or a problem with the washer system for the wiper?

6- Do any other modes work? The default position for the HVAC system when engine vacuum to the control head is not present is defrost.

7- You do need to have someone with a full feature scan tool access the EBCM (electronic brake control module) to read the ABS codes. It does not have to be a dealer, but they will have to have a rather expensive scan tool.

 

Thanks, now that its warmed up again, I can check some of this out later. I hope it's the switch, encoder motors aren't too cheap.

2-I do have a blacklight so I can check for system leak a bit later.

3-Should I have a professional flush the dexcool out and fill with something different? My step father-in-law somewhat halfway flushed it, but not enough to convince me that it didn't have gunk in it.

5-The rear wiper works fine, but no washer fluid comes out when you push the washer button.

6-All other modes work, except direct floor and the defrost/floor.

Thanks for the help, you've given me plenty to do today.

 

You can flush it yourself with a garden hose. I would remove the heater core hoses from the engine and put a hose into one, then the other to forward and back flush the core. Do this until the water flows out clean in both directions. If you cannot get it to flow good that way, you may have to be more aggressive.

I would check the washer pump first. It is the upper pump in the washer fluid reservoir. You can test it by disconnecting both pumps plugging them in opposite. If your windshield gets wet with the plugs reversed, you know the pump for the rear is getting power and the pump itself is bad or the line to the rear window is clogged or otherwise obstructed. If the windshield does not get wet, but the rear window does, then there is a problem with either the wiring or the switch itself.

As far as the HVAC system, it sounds like you have a bad defrost/floor actuator.

 

+1. Ford Taurus's are notorious for this also and I did the same thing as Kyle suggested. Just becareful where you do this....espically if you have pets or small children. I lost my radiator on my jeep a couple winter's ago at my brother's house....didn't know it until I was quite a distance from his house nor did I think it happened at his house. One of his dog's drank some of it that was in the driveway and died.

The problem I had with my Taurus is that this would work for a few months and then every time I did it, it would take less time to block up until I finally replaced it. When I did replace it, I bypassed the heater core and had the system flushed (this way none of the crap still in the coolant would get into my new heater core), then when I got back home I hooked up the heater core hoses and its been fine for a couple years now.

 

I flushed it quite a bit better than my step father in law did, heat comes out hot enough to burn you now. This will get me through the cold snaps of spring now anyways. I had a cat drink antifreeze when I was younger, so I'm gonna keep the dog indoors for a few days. I did spray the area down pretty good afterward, as there are cats that run around, hopefully that'll dilute it enough to where it won't hurt any of them should they drink any.

I filled my washer fluid tank up about a week ago, I checked it today any it's nearly empty. I'm guessing the leak may quickly run the fluid level down too low for the rear pump to pull anything. The power mirrors are working great for now too.

I also disconnected the battery and reconnected it. After doing so I could get the 4wd hi to light up for a few minutes, but it's back to not lighting up again. I don't think it ever really went into 4wd honestly.

I thought I had a black light somewhere, but I can't find it, so I haven't been able to check the ac for leaks.

 

Good deal on the heater core. A flush can do wonders!

Let us know how things work out on the rest of the issues.

 

Are washer fluid reservoirs somewhat universal or am I going to have to stick to the 98? Haven't worked much on any of this, cuz my to do list seems to be getting longer and longer. I did put my lighted pedal covers on though, first vehicle other than my 86 s-10 that I felt like fooling with such.