Replaced switch, still no A/C

[94v6GT]

went and bought a refill w/ gauge kit. gauge said it was full so i replaced the low pressure switch at firewall. now i see/hear compressor kick on for 1 second then off for 3 continuously.

gauge will show pressure waaaaay high!, until compressor kicks in then it drops way low.

what now

 

[fish254]

those refill gauges dont work i had the same problem u dont have enough gass for the compressor to kick on!!

 

[HISSIN50]

Agreed. For the low pressure reading to be valid, it has to be viewed after the compressor has been engaged for a few seconds.

 

[94v6GT]

so its still low then? ok i'll try adding. i jus didnt wanna risk anything (mainly my safety)

 

[BlownFiveLiter]

Chances are it's still low. Once the pressure equalizes across the high and low sides, the low pressure switch turns the compressor off. You can jumper the terminals in the harness to force it to run, so that it will accept more refrigerant.

 

[HISSIN50]

so its still low then? ok i'll try adding. i jus didnt wanna risk anything (mainly my safety)

If you don't want to risk your safety, have a shop check it over.

Always use proper manifold gauges (they're accurate and allow you to see high-side pressure, which is huge).


If you are concerned about the mass of charge, post up your low and high side pressures, along with ambient temps.

Good luck.

 

[94v6GT]

I proceeded to empty most of the bottle into the system. the compressor continued to cycle on and off, but the A/C does blow cool now?
the gauge alternated between 45-50(off) and 25(on). i would guess ambient was around 70-75 degrees but the engine was warming(idleing 10-15 minutes)

I think the system at some point stopped accepting refrigerant. it blew the hose out of the fitting between the gauge and the bottle so i will probably jump the switch to keep it cycled 'on' and hopefully a fresh bottle will get it icey.

If these gauges are ineffective ($20 for bottle w/ guage) do i just continue filling until the compressor 'stays' on??

 

[HISSIN50]

I proceeded to empty most of the bottle into the system. the compressor continued to cycle on and off, but the A/C does blow cool now?
the gauge alternated between 45-50(off) and 25(on). i would guess ambient was around 70-75 degrees but the engine was warming(idleing 10-15 minutes)

I think the system at some point stopped accepting refrigerant. it blew the hose out of the fitting between the gauge and the bottle so i will probably jump the switch to keep it cycled 'on' and hopefully a fresh bottle will get it icey.

If these gauges are ineffective ($20 for bottle w/ guage) do i just continue filling until the compressor 'stays' on??

The low side pressure should change when the compressor is engaged (like it will go from 30 to 20 PSI, etc).

Manifold gauges are the only way to really know what's going on. You dont want your high-side reading to be too elevated.

You also don't want to just fill it till the compressor stops cycling. The best way to know what's going on is to measure the mass of refrigerant placed into the system. After that, noting high and low pressures with regard to ambient and vent temps, and using a P-T chart, can get someone close.

 

[94v6GT]

update: so i bought another refill bottle and put about 1/2 of it in. compressor still goes on and off intermitently blow A/C blows icy cold works for me!