A/C compressor short cycling, a bit of advise please.

evilunclegrimace said:

The compressor runs for 10-15 seconds and cycles out and repeats. Any help would be appreciated(I am not an A/C guy)

Click to expand...

evilunclegrimace said:

Here is a video of the gauges;

Click to expand...

PlayingWithTBI said:

Do you have a set of manifold gauges? It sounds like it's low on refrigerant but, other things may be in play, like plugged passages, stuck valve(s) in compressor.

Anyway, watch your low side gauge to see if it gets sucked down while you high side goes up.

If the low side goes under ~25 PSI, the pressure cycling switch will shut off the compressor until it gets up over ~45 PSI.

If the high side goes up over ~430 PSI, the high pressure switch will shut off the compressor until it drops below ~250 PSI.

If they're both within range, maybe your compressor is cycling due to a circuit breaker popping due to high Amp draw.

Note: you pressures may be different than what I used but, should be pretty close. YMMV

All I see is a picture of it shut off, I'm assuming since they're both equalized.

Click to expand...

evilunclegrimace said:

I am trying to get a video to load give me a minute,I am not a computer guy either.

Click to expand...

evilunclegrimace said:

OK,1998 K1500 Suburban,5.7 4L60E. The truck came with the A/C system inop. I finally got around to repairing it. I have replaced the following due to the fact that the system was open when I bought the truck, drier, condenser, orifice tube, compressor ,high pressure switch and the hose assemblies.Also all new "o" rings that were lubed with Pag oil. The evaporater core in the dash was flushed twice.

I vacuumed the system down for 1 hour and it held vacuum over night,8-9 hours.The system has 8 oz. of PAG 150 as per the compressor manufacturer specs. I have 36 oz of R-134a in the system(as per manufacturer) The compressor runs for 10-15 seconds and cycles out and repeats. Any help would be appreciated(I am not an A/C guy)

Click to expand...

evilunclegrimace said:

the high side hits 435 psi.and the low side drops to 60 psi. and then the compressor cycles out. The compressor cycles back on about 180 psi on the high side and 82 psi on the low side Every thing in the system is new.

Click to expand...

L31MaxExpress said:

At 435 PSI you have a restriction in the high side or lack of airflow across the condenser.

Click to expand...

L31MaxExpress said:

Front ac only? My 99 Tahoe with rear air is 11 oz PAG and 64oz which is 4 lbs of R134a. My Express van with aftermarket rear air takes 12 oz PAG and 68oz R134a per the specs.

At 435 PSI you have a restriction in the high side or lack of airflow across the condenser.

Click to expand...

PlayingWithTBI said:

I was just going to ask if you radiator fan(s) are running? If so, it looks like it's overcharged. If not, Like @L31MaxExpress said, you have a restriction but, the low side is going down slow too so, I'm leaning towards overcharged. Ambient temperature will affect it too.

Click to expand...