I'm having problems with my A/C too. The black wheel/clutch thing on the drivers side (condenser?) continually stops and starts, every several seconds. I don't have to tap it though. Sometimes I have 3/4 cooling out my dash, mostly zero cooling. If I stop the truck after being driven........when I start it up again, the air is bloody hot. My mech said there are no leaks and there is enough coolant in the system.

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I finally found a possible answer on here for my NOT cold A/C. That service bulletin................that first said to change fan clutch. Then revised to say to first try a reprogramming (which makes the fan come on more often).

QUESTION; Can any shop do that? Or do I have to go to the dealer? And what do any of you think that may cost?

Thanks

 

Your symptoms sound like a low charge level. A simple recharge may be all that you need, however, I would advise a new thread on your problem if you haven't already done so. Your symptoms are different enough from the OPs and it would not be kind to hijack this thread.

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If I remember the TSB you are talking about, you might want to check the application. Reprogramming of the fan clutch (engine cooling fan) would require an electro-viscous clutch fan that's lockup rate is controlled by the PCM. The S-series trucks did not have such a fan clutch. They only came with the thermo-viscous clutch which lockup was varied in response to the temperature of the air flowing over the coil in the front.

If it were applicable, reprogramming is typically a dealer thing. Most independent shops do not get GM updates. You'll probably pay at least an hour of shop time for the reprogramming and rates vary. My local dealer is over $75/hr shop rate the last time I checked which seems to be on the cheap side from what others have stated in their areas.

 

Thanks.

And sorry for confusing my posts, people. Can someone bump them to that other thread about A/C??

 

*Moved the A/C related posts from the 4Lo - Overrevs then clunks into gear on takeoff thread to a new thread and combined other posts by the author and myself from another member's post here*

 

Thank you.

 

Tony ZR2:Couple of conflicting items in your posting; coolant and refrigerent are two entrily different things so when your mechanic says there is enough coolant in the system....not sure if your mean refrigerent or actually engine coolant???

The AC compressor short cycling is due to system pressure, usually low, which means low on refrigerent. Suggest taking Blazer to an AC shop and have them put the gauges on it and check it.

 

Why do you need ac in Canada? Take it all out, lighten things and a smidge more power

 

Well since my posting is about my A/C not being cold enough, I thought the word "coolant" was obviously referring to my A/C. And not the engine. I used that word because I can't remember what that gas is called. R-12?? Some people here still call it Freon.

About 6 months ago, it was tested by my mech. He said it was not low and there are no leaks. At that time it was maybe 3/4 cold, most of the time. Sometimes less. Now, it's mostly zero cold, with once in awhile a bit cool. Back then, my mech. said when they put a large fan in front of the rad............THAT made it full cold. And said I needed a whole new clutchfan (but recommended an elec. of which I'd like myself). However THAT..........ended up making no sense to me. Why? Because, sometimes I'd be driving around in town...and it would be kinda cool. But sometimes when I'd be on the hwy, where I'm sure there's just as much air as my mech's biiiig fan, going through my grille.............ZERO cool.

Also, I just called GM. The tech said that compressor clutch thing on the DS, should only be clicking on and off about once every 30-40 seconds. But mine does about every 15-20. So the guy says......I should be low on refridgerant. *groan*

 

It sounds like the classic symptoms of low refrigerant--the too frequent recycling of the compressor. The cheapest way to check it is to charge it with a DIY product called AC Pro. It has replaceable canisters and a fitting with gauge. Look in the auto parts stores like, AZone, Advance Auto, and so on. Go on line to read how to do it. at ACPROcold.com This site has step by step and also a 'port locator' so you will know where to hook up.

 

Thanks.