Air Conditioner Compressor

[mattm232]

I have a 95 Z28 and have been having some trouble with the compressor coming on. Seems like sometimes it will and sometimes it won't. It needed charged and have been trying to charge but am having no luck since the compressor won't kick in. Any advice on this? Also does anyone know if you can buy a hard start capacitor, like they have on home split systems, to help fire the compressor. Any help I would appreciate!!!!!!!!!!!!!!!!

[ilikelife]

First, Make Sure The Charge Is Properly Done. And The Ambient Temperature Is Over 4 Degree.
Second, Check The Electrical Problem. The Z28 A/c Clutch Is Controled By The Pcm, When The A/c Swith Is On. The Pcm Close The A/c Relay, And Then Send 12v To The A/c Clutch. So Check The Relay And Make Sure The Current Flow To The Clutch When The Switch Is On. If Still Not, Check The Continousity Of The Wire. If It Is Good. Clutch Is Gone.
If After The A/c Switch Is On, No Signal From The Pcm To Engage The A/c Relay, Check The A/c System Pressure Sensor, Wot(wide Open Throttle)sensor And Ect( Engine Coolant Temperature) Signal To The Pcm. Those Signals Control The Engagement Of The A/c Relay. If They Are Good, Replace The Pcm
By The Way, Don't Forget To Check The Ground For The A/c Clutch, It Is Located On The Left Side Of The Engine.

[Scrapper]

it wont kick on if there's not enough freon in it.but before you charge it you need it pump out to get all moister and freon out first. but but look at air hoses if there will be oil on them if were leaking down.but this is the the way to do it iff your going to do it right.good luck....

[shorod]

The start-up capacitor is used with alternating current (AC) systems to smooth out the in-rush current and maintain the power factor, keeping the circuit breakers and the power grid happy. You don't have such an issue with the DC field coil on the A/C compressor. If the compressor clutch is not engaging, it's not because you need a start-up capacitor, it's because there is a problem with the system that needs to be remedied.

One thing that hasn't been mentioned yet would be to check the gap between the compressor clutch plate and the field coil. If that gap is too large, that could explain why the compressor works sometimes and not others. You could also have a field coil in the clutch that is starting to fail, or it could be contaminated with oil if the compressor seals are leaking.

-Rod

[curtis73]

If I can't get the compressor to run (and I'm sure the rest of the system is OK, like no clogs in the expansion valve, etc) I just hotwire it from the battery to the compressor. That makes it run

[UncleBob]

if you're trying to charge the system with no measuring or more importantly, vacuuming the system down first, you're going about it the wrong way to say teh least

You will be leaving oxygen in teh system with this method, let alone the amount of freon will be unknown. Not a good way to go about it

Not very helpful, but take it to a shop

[curtis73]

When I said "the rest of the system is OK" I should have included "vacuumed system."

[tripletdaddy]

A "discharged" or low charged system hasn't necessarily taken on any air or moisture. That won't happen until it has near or at zero system pressure. A system below 45 psi at the low side will not come on, but the system can still have pressure in it, but it has not completely leaked out and may not at least for awhile. If it has pressure, even if it is below 45 psi, how could air and moisture possibly get into it? Only if it is COMPLETELY emptied out to a gauge pressure of zero, due to whatever reason, leak, breach, disconnection, etc., will it take on external contaminants that can be drawn in by the expansion and contraction of the "gas" inside the system due to temperature, sort of like it's "breathing." Otherwise, it will not, and it can not take in anything. It has to obey the physics .