99 Blazer Heater not working And Yes i Read Threads

[Kay1210]

Ok heres my situation my heater is not working but i think my situation is a little different that what ive been reading. My heater will work fine in the summer (Expectedly) but i mean on chilly summer nights. It will work in the initial conversion for fall to winter. When the weather gets cold and stays cold it stops working. I have a hard time believeing it is the T-Stat it could maybe be climate contol. It is a manual not digital. I read about the core being flushed Do you think that would help given my explination of my problem? And I have no clue what a blending door is? LOL Im not the most experience mechanic. This has happened to me 2 years in a row now and i cant take it anymore? Please Help!

[Rick Norwood]

Originally Posted by Kay1210

Ok heres my situation my heater is not working but i think my situation is a little different that what ive been reading. My heater will work fine in the summer (Expectedly) but i mean on chilly summer nights. It will work in the initial conversion for fall to winter. When the weather gets cold and stays cold it stops working. I have a hard time believeing it is the T-Stat it could maybe be climate contol. It is a manual not digital. I read about the core being flushed Do you think that would help given my explination of my problem? And I have no clue what a blending door is? LOL Im not the most experience mechanic. This has happened to me 2 years in a row now and i cant take it anymore? Please Help!

Start with a good back flush on the entire system especially the heater core, and replace the T-Stat. A good Reverse Power Flush would be even better. Be sure to Replace the rad cap with a Stant cap. The Flush procedure has been described in numerous threads. Then report back to us and let us know if that solved your problem.

[Kay1210]

I read about flushing but i didnt see anything on the actual procedure can you post a link to what the actual procedure is.

[Rick Norwood]

Originally Posted by Kay1210

I read about flushing but i didnt see anything on the actual procedure can you post a link to what the actual procedure is.

This was originally posted by Blazee in the Heater Core Flush Thread:

Buy a Prestone Flush N Fill kit, it is a "T" that you install in your heater hose so that you can connect your water hose straight up to it and back flush it. Then use the Prestone Radiator Cleaner. Not the "flush" get the "cleaner". The flush is used for twenty minutes while idling. The Cleaner is used for 3-6 hours while driving, you just drain your system add the cleaner, fill up with water, then drive a few days with your heater on (you don't have to have the fan on, just the temperature control all the way up), then when you drain it all the sludge comes out leaving your radiator and heater core spotless. Then connect your hose to the "T" again and back flush one more time, this will get everything out.
After that Fill with a 50/50 mix of DEXCOOL ( or the green if you prefer, at this point your system is clean enough to convert) and distilled water. NEVER MIX THE TWO COLORS OF ANTIFREEZE! You will have to keep topping it off over the next few days as the air is worked out of the system.

AND THE ABSOLUTE MOST IMPORTANT THING IS TO REPLACE YOUR RADIATOR CAP, WITH ONE NOT MADE BY AC DELCO. THE AC DELCO ONES THAT CAME ON THESE VEHICLES ARE DEFECTIVE. THAT IS WHAT CAUSED YOUR PROBLEMS IN THE FIRST PLACE. THE BEST ONE TO BUY IS THE "STANT" BRAND YOU CAN PICK THEM UP AT ADVANCE AUTO FOR ABOUT 5 OR 6 BUCKS.

The Prestone Flush N Fill ($4) and the Prestone Radiator Cleaner ($6) can be bought at any parts store and walmart.

[tokes]

I had the same problem with my 98 Blazer and just did a backflush and now I could boil water on the defrost and melt your shoes on the floor heat. I would suggest you just take it to a reputable radiator company and get them to do the back flush. That way you don't need to worry about dealing with the antifreeze all over the place and they pobably have done thousands of these. It cost me $93.00 to get mine done.

[91s10blazer]

In my 91 blazer, the vents dont work at all. Ive made it since the beginning of last summer with no A/C, no heat, no defrost, no nothing. Anyone got any suggestions?

[tokes]

What do you mean by the vents don't work? Are you saying there is no air coming out of any of the vents/defrost floor etc? If so I would say start with the fuses on the fan and then the fan switch and then the blower motor. If you are getting air but no heat then look at getting your core backflushed.

[91s10blazer]

Thats what Im saying, no air at all is being blown through the vents. Winter without heat and summer without A/C BLOWS!!!

[Rick Norwood]

Originally Posted by 91s10blazer

Thats what Im saying, no air at all is being blown through the vents. Winter without heat and summer without A/C BLOWS!!!

You might want to start your own thread. Check the blower motor fuses and the fan motor.

[BlazerLT]

The first thing that should be asked is how far the temperature gauge goes up when the truck is fuly warmed up.

1/4? 1/2?

[Kay1210]

Who would be a reputable radiator comapny? Someone like Midas?

[Kay1210]

Also I can get a new heter core for $68 I could just put a new one on rather than backflushing for $93 but maybe it would be better to flush the whole system what do u guys think?

[blazee]

I don't believe you know what all is involved to replace the heater core. You have to dismantle the dash to get to it. If you have it done it will cost the price of three flushes. You can easily flush it yourself and save a lot of $$.

[tokes]

Rolling the dash is a pain and not something you want to do unless 100% required. Backflushing the core is not hard, just make sure you have a place to do it. I didn't do it because I didn't want to deal with discarding the old antifreeze and making a mess in my garage (home to my 2001 Harley & 1967 Malibu).

Look in the yellow pages under rad repair and call around a bit for prices, just make sure you are clear that you want the core "backflushed".

[Kay1210]

Ok so you are saying follow what rick was telling me to do. And that should backflush out the heater core.