(Bleeping) Air Conditioning....

[Simbolgades]

I need some help confirming or dispelling my belief that the local automotive quack shack overcharged my A/C system.

The Story: A few months ago, after much fiddling, sweating, and swearing, I got my blower motor working again. (I posted pictures of the incinerated ACC2 relay...search for 'blower motor'...) To my surprise, the A/C fired up and began cooling. Joyous.

That was in April. As summer rolled on, and with the mercury climbing ever higher, the feeble charge in the system just wasn't getting the job done. So I took in to have the system topped up. 1 1/2 pounds of R12 and 90 bucks later, I thought I'd be good to go.

On the ride home, the engine started to surge, sometimes violently. I killed the A/C, and the problem stopped. Further testing at home revealed that the surge was caused by the compressor clutch disengaging and reengaging in a somewhat random fashion.

Frequently, when the clutch suddenly disconnects, the ecu continues to tell the engine that the compressor is still on, so the idle shoots up to about 1600 rpm.

The Problem seems to be temperature related. The A/C works just fine in the morning when I go to work. (Usually around 5:15am - ambient temp around 75 deg F.) It surges if I try to run it in the afternoon on the way home. (Around 2pm - ambient temp between 95 and 100 deg F.)

The FSM lists the system refrigerant capacity at 1 1/2 pounds, which is exactly what they put in. Since the system WAS cooling, albeit weakly, SOMETHING must have been in there, right?

Is this just the dual pressure switch cutting out, or is my compressor FUBAR?

Please help; August in Texas with no A/C is a preview of my front seat in hell!

TIA

Chris'92 coupe

[fatboy]

you're reasoning for overcharging is incorrect. when you charge a system like that, you reclaim the old refrigerant, put the system under a vacuum (cause theoretically if you can hold a vacuum, you can hold a charge), then recharge. they would have to be the biggest d!ck if they didnt. for your problem though, check the high pressure switch and low pressure switch

[Simbolgades]

Further reading of the FSM sheds some light on the problem of the compressor turning on and off:

'This condition (compressor cycling) indicates a malfunction in the system.'

Well no s***...

Chris'92 coupe