Ac quite workin just after I installed my Pacesetter headers. Dont know if it is related but here is what's up.


Turn ac on, pump stays off, electric fans stay off. I get ambient temp. out of vents

Through HPTuners force ac pump on, pump kicks on, fans kick on. Still get ambient temp. out of vents.


Anyone have an idea on why it is doing this? Low freon or something? Any help would be greatly appreciated as I leave tomorrow morning on vacation and I would really like to have my ac working. Thanks guys!!!

 

If you're manually turning the compressor on and it's still blowing warm, it sounds like the freon is low. Best bet it to get a set of ac manifold guages on it and see what they read...that would be my starting point.

 

Is the area of the hoodliner directly above the A/C pulley clean? Or is there oil slung all over in a nice straight line?? Sometimes that is indicative of a shaft seal saying bye-bye. But like Bud said. Get some gauges, check HI/LO side pressures. HI side should be relatively high and the LO side should be low. Could have a pressure switch problem too. If you have good pressures, check your pressure switches next!!

 

Just did my 2nd pacesetter install this weekend, both on lowered trucks on jacktands and on both I had to brop the pass. side header from the top. Removal of the ac dryer was necessary due to interference with the ac lines and such, had to recharge the ac. That being said did you go from the top or the bottom? Possable you could have damage a seal/line/fitting and leaked the freon out or left the pressure switch unplugged? Sorry to correct you 99silver6.0 but on the 5.3 ac comp is on the bottom left so oil would be present on the frame/fenderwell and no so much on the hood liner unless it was slung by the belt?? Put it on some gauges, high side should be around 250-300 and low side 60-80 with compressor on. Pressure swith is a very common prob as well and cheap and easy to replace with no loss of freon, you can check it by using a jumper wire accross the plug, will force the compressor clutch to engage. Probably a low freon situation due to a leak or something?

 

Ok, so check the freon level, pressure, first. I already forced the ac pump on with my scanner, and I didnt get any cold air. So even if my pressure switch was gone it still wouldnt fix the problem right? Can I get the gauges at a local auto parts store or would you guys recommend taking to shop since they might have to put freon in anyways?

 

if you think you might have a leak def. take to a shop unless you want to start doing ac work , because ill tell ya the dyes are a gimmick ive never seen one that works. you will need the electronic leak detector and they are $3-400

if you dont think you have a leak, get some gauges and see what it has. autozone used to have them (gauges)

 

before they waste dye or electronic detector, they'll throw a vacuum on the system to see if it holds vaccum. It's the cheapest and quickest way to detect the fact that you have a leak or not. The detector will help narrow done the location of the leak.

 

Aint no thing. Guess this is my daily memory lapse. I just replaced a compressor on an E-One fire truck tuesday night.... Guess thats why I was stuck on top mount compressors. Oh well.

 

Only bad thing about that vacuum based leak test is it will not always tell you if you have a leak. When you put it under that vacuum, if you have an o-ring or whatever leaking. That vacuum pressure will often times cause the leak to seal up. Thus hiding that often possible, minute leak. Best method is a sniffer or dye.

 

yep yep, gauges are point less unless you have a spec sheet from G.M showing what the pressures SHOULD be at the ambient temp, (pressures will change with temp) the only other way to tell if the system is low is to recover the refrigerant. Pull a vacuum and boil the moister out. It must pull at least 20" or closer to 30". You can also use nitrogen to check for leaks, but you would have to recover the system and fill it. Then check for leaks. I haven’t had much luck with "sniffer" I like the dye as it has always worked for me. But the easiest way to look for a leak is to look for an accumulation of dust around all fittings, sensors and compressor seals. The a/c system switches are a common point of frailer, but the fact that you can command you a/c clutch and still have hot air would leave me to believe that your system is low. DO NOT run a compressor with low refrigerant. All the oil will be pumped out and the compressor will lock up.