How often should the AC clutch engage and disengage?

My AC didn’t want to work when I turned it on this morning.
After turning it on and off a few times it started working.

My father checked the Refrigerant. I don’t know if it was low. All I know is that the High Side would go to 150~. And the low side low drop to 20~ and then go up to 50~

Anyways, my AC compressor clutch seems to cycle On and Off a lot.

I timed it. It’s on for 8 seconds and off for 30 seconds. It very consistent, with a half second every cycle?

This doesn’t seem good for the AC Clutch?


Only thing I’ve done recently was replace the battery. And I can’t see how that would have any affect on the AC?

 

Sounds like it's low on refrigerant, low side shouldn't be that low unless the evaporator temp is really low.

 

Beats me
As of now the temp coming out of the vents is 46 degrees. Temps outside was 61.

I don’t know anything about AC systems.
My father acts like he does, but I’m not sure he really knows what he’s doing.

You’d think he would have said something. I was standing right there watching the Low side gauge go up and down. That is what got me thinking something wasn’t right.



It had a slow leak after we disconnect the the low side gauge from the valve.

Like I said, I pressed down on the valve with a screwdriver to reseat it, and it seemed to stop. Some neon green stuff came out. Probably dye or something. It wasn’t bubbling like before. So that why I think it isn’t leaking there anymore?

I’m just going to prepare for a hot summer and no AC. Something tells me it isn’t going to last long

 

That seems about right then, the evap temp sensor will cycle out the compressor at around 35 degrees to prevent freeze up and come back on at around 40 degrees.
Check and see if your suction (larger) line is nice and cold with the A/C on, if it is your refrigerant charge is probably pretty close, if it's not then it's likely low or there's another problem.

 

When I converted the mpa to psi, they seem to be pretty close to what I was seeing?
Does this make sense?

To check the system it said to have the engine at 1,500 rpm.
I was at idle? And outside temp was 61. But it was still close


Test conditions:

1. Engine has been warmed up.
2. All doors are fully open.
3. A/C switch is ON.
4. Engine is running at 1,500 rpm.
5. Air inlet mode selector damper is set at recirculation.
6. Temperature control switch is in MAX. COLD position.
7. Blower speed control switch is in HI position.
8. Air temperature at the air inlet is 30 to 35°C (86 to 95°F)

1. When the refrigerant volume is proper:
   
   Gauge reading:
   Low pressure side:
   0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm2)
   
   High pressure side:
   1.37 to 1.57 MPa (14 to 16 kgf/cm2)

 

What the previous poster said, sounds normal for a 61 degree day. Close the doors and windows, put the system in recirc and check the air temp coming out of the vents again. Try to do this when you're driving it around too: Air pushing through the condenser while moving makes a big difference, especially on a vehicle without an electric fan out front. When the refrigerant gets low enough, a sensor will detect it and lock out the compressor to protect it. It needs refrigerant and the oil it carries to lubricate and protect it. Some systems will also on-off rapid cycle the compressor to do the same thing if the charge gets too low. The leak at the valve connection was probably because it hasn't been touched in a long time. The cap also provides a seal. The green dye was exactly that: it is to help a tech identify/find a leak. It glows under special light.

Be extremely careful of liquid refrigerant: a drop of it hitting you will freeze instantly. You don't want it on your eye. Wear safety glasses. My compressor does not run below about 40 degrees. My other vehicles are the same way.

 

That is what I did, air temp was about 46 out of the vents. And that was checking it with a cheap harbor freight thermometer.

I didn’t check it while driving. But I can.

That’s my guess too

I think my cap had a hole in the center of it. I’ll check again tomorrow.
But I don’t think that plastic cap is going to seal much?

Thanks for the advice. I definitely was not wear safety glass.

 

You're right about the cap: It's main function is to keep dirt out of the fitting. Mine looks like it has a hole in it too. I think it's just an indentation. I think the valve part is a simple schrader-valve like on a tire. You should expect to see a lower temperature out of the vents when you are driving it, but 46 doesn't seem too bad. Good luck!

 

Sounds like the clutch is short-cycling, common on a system that needs a recharge.

Look around for leaks at the condenser and fittings, the service port Schrader valves can wear out and leak slowly

 

You may be right, I didn’t look too hard at the cap.
The valve looks like the type in a tire valve stem, but bigger.

While AC is important, it’s not on the top of my “need to fix” list.
I need brakes first. I’m still on OE shoes and at 74k on the front pads. They are both “at the limit”.
So those are my priority first.