My A/C wasn't running properly since I bought it(about 6 months ago), probably due to a leak from a loose connection at the compressor. Had a bit of green spray into the underside of the hood. I'm thinking it's some kind of dye or a/c oil since it doesn't smell like anti-freeze.

On a side note, does the a/c system use the same radiator as the engine coolant, or does it have it's own condenser? Saw the hose run from the compressor down towards the radiator but wasn't able to see the connection.

Anyway, I bought a recharge kit due to the leak assuming it was just the system having low pressure. When I hooked up the new bottle and the guage, it said it was sitting at just under 30PSI. So I filled it with to about 50PSI. The compressor still wouldn't run on its own. I had to jump the cable connecting to the evaporator(silver cylinder) to run the compressor.

This works great and the vents blow cold as expected. However, if I hook the cable back up, no joy. A smack to the evaporator got the compressor to kick on briefly, but that only worked a couple times, seemingly random.

Could I still be low(It's about 90F here) on refrigerant even though I was redlining the gauge? Would it be dangerous to go a bit higher in pressure? Or is the problem something more serious?

 

it might be the pressure switch on the evaporator. check for lose plug or switch its self.

 

What's the location and appearance? This new chilton I have is worthless.

 

sorry not on the evaporator, its on the accumulator. its the thing that looks like a beer can.

 

Sorry, I misused the word evaporator in my original post. That was the accumulator.

So where on the accumulator is the switch? Is it at the same spot where the cable I had to jump connects?

If so, nothing seems loose as I spent some time wiggling that around and the jump using a paperclip at the connector suggests the wires are just fine.

 

That "cable" you unplugged and jumpered connects to the pressure switch. If you look at the accumulator where it connects, that piece is removable and replaceable.

 

The "green spray" is most likely a mixture of refrigerant oil and UV dye. The dye was injected into the system to help locate leaks. The refrigerant does not go through the radiator. It goes through the condenser, which is located in front of the radiator. Both connections are on the passenger side, close to the bottom of the condenser. They are both visible if you look straight down along the passenger side of the radiator tank.

The Harrison HT6 compressor, (original equipment) is well known for "belly leaks". The compressor housing leaks where the two compressor halves come together. If it's not leaking now.... it will

As for adding more refrigerant.... The recharge kit that you bought will monitor low side pressure only... totally worthless, just like the Chilton manual. These systems are very sensitive to the amount of refrigerant, and oil in the system. Too much or too little of either one will either damage components, or cause poor AC performance. The amount of refrigerant in the system can not determined even by monitoring high and low side pressures simultaneously. The only way to determine how much refrigerant is in the system is by draining, evacuating, and recharging with the proper amount. All 3 steps must be done. The compressor does not have a "crankcase" or "dipstick". Refrigerant oil is in suspension with the refrigerant and circulates throughout the system with it. When refrigerant leaks out, so does a certain amount of oil. If/when the amount of oil in the system is too low, the compressor will fail, usually causing other damage in the system as well. Checking the amount of oil in the system is an involved procedure so a small amount is added, usually 1 to 2 ounces, each time the system is recharged.

Without the proper training, knowledge, experience and tools, AC diagnosis and repair should be left to a professional. The risk of destroying AC components, and causing physical harm to yourself are real.

 

Know if the low pressure switch can be replaced without evacuation or loss of refrigerant?

I'd like to do this myself for various reasons and I'm willing to accept any risk.

And Captain Hook, thanks a lot for the detailed information. Understanding a system is most important when troubleshooting it.

 

The clutch cycling switch, (on the accumulator) can be replaced without discharging the system. There is a shrader valve in the accumulator so when you remove the switch, you'll get a slight hiss until the shrader seals shut. Same thing when you install the new switch. Hand tighten only, no tools!

 

The connection appears much larger than a shrader. The nut portion of it looks to be about 3/4" or so. Maybe it's just hiding a shrader valve under all that.

I got a replacement low pressure switch but it appears that it needs some kind of housing or something. I'm guessing the metal case and nut portion of that connection is what I have to insert this switch into with the new o-ring. Going to try and disconnect it this evening unless I hear otherwise here.

Thanks.