And still no a/c

I replaced the liquid line and orifice valve. Pulled and held vacuum no problem. I go to charge it and the same shit again. Compressor cycles on and off regardless of pressure. It just won’t stabilize no matter what. I also noticed that my temp control might have a problem as well. With the car running and a/c on if I move the temp control just two clicks from full cold I get blasted with heat. Related?

Not sure what started all your problems but if you're replacing the orfice tube that usually means debris in the system. Have you actually flushed the system?

How long did you vacuum?

Also make sure you put the orfice tube in the right direction.

If the compressor is cycling, but you state you have an issue with the temp control, I would probably address the temp control issue before you dig much deeper into the ac system.

The temp control is a cable drive POS. Make sure you address that.

Temp control sounds like the blend door as mentioned but that has nothing to do with the compressor cycling.

What are your pressures doing as it cycles? Do the both sides even out once turned off and if so how quickly? It takes a bit for it to suck down enough freon to stay running when filling it.

if pressures are in spec could just be a bad pressure switch too

The compressor was cycling on and off. I thought I had a clog in the system because I found a can of a/c pro in the trunk when I had bought the car. I used that crap in my Expy once in a pinch and it clogged my orifice valve so I thought that was the problem. Orifice valve wasn’t clogged.

I just did a static temp relation test and that’s showing I’m still low on refrigerant. I get 65psi on both sides and it’s 90* out. According to the manual I should have 34oz in the system but as it is I’m seeing 225psi high side and 25psi low side. So far the car has 30oz in it and I’m afraid to go higher
I jumped the a/c switch which kept the compressor on steadily and was able to get these readings

Yup..the compressor is taking small sips when putting new freon in. It acts like nothing is happening at first. I put mine in the high ac switch setting.

30 oz might be ok for now..depends on the temperature outside too...I think.

The other problem sounds like the blend door cable is coming off. Make sure you note the routing of the cable before you go mucking with it. It is held in place by the routing itself and can spring loose otherwise.

You may just be able to push it on to the blend door flap and not disturb anything.

You will need to pull the radio or it will be a miserable job to get at it otherwise.

I would check the other end of the cable connection behind ac controller first.

The cable is adjusted with the dial all the way cold or hot as the blend door flap will drop to one extreme by gravity when the cable is disconnected..then pushed back on. You can tell by looking how the blend door tab lines up with the switch at either extreme.

I think I took some pics of the cable routing.

This sucks.

In the manual there are notes about the cable

I remember when I did the heater core the manual helped on how to

Along with pictures of box and doors.

65 on both sides in that heat tells us you are low on R34 and have a leak OR you did not fill the requisite 34 oz. you should read a psi per degree F outside.

Also, pressure can be misleading if you have air in system in place of the Freon you need to keep the compressor from cycling.

Did you bleed the fill line when you filled it? If you do not, since it takes 3 fills, you could have air in the system.

Also, did you replace the accumulator? They needed to be done for many reasons when the lines are open.

I pulled vacuum after I swapped the liquid line but I didn’t bleed the hoses prior to filing. I only swapped the line didn’t change the accumulator

Robinair 40396 is the purge fitting.

Also when you put a vac on the system, leave it for an hour. That is what gets the moisture out of the system. Vac lowers the boiling point of water and it gets pulled out by the vac.

You especially want this to pull the moisture out of the dryer/accumulator/catch can.

Ok there must be a clog somewhere. I swapped the a/c switch and the compressor still cycles. While the car is running the high pressure side rises to about 240psi and the low side slowly drops to about 22psi which is where the compressor shuts off. The high side then drops to about 150psi while the low side rises to about 50psi which is where the compressor kicks back on.

So I guess there is a blockage somewhere and the compressor is sucking the low side dry and shutting the compressor down. Where could it most likely be? The accumulator? One thing I just got was a bunch of that uv leak detection dye when I went to disconnect the hoses. I didn’t put that in there so I don’t know how much there is. Could that be filling the accumulator causing a blockage?

what did the old orifice tube look like - was it clogged up? If so there might be a bunch of crap in the system that just clogged the new one up too

The old one wasn’t clogged

Put some gauges on it and take a couple hundred psi of air or nitrogen and try blowing the obstruction out.

To be more technical though, it is probably blocked up at the metering device which is (in non automotive units) at the entrance of the evaporator.

the filter drier should also be replaced every time the system is opened to the atmosphere because it’s job is to absorb moisture.

03yllwguy said:

65 on both sides in that heat tells us you are low on R34 and have a leak OR you did not fill the requisite 34 oz. you should read a psi per degree F outside.

Also, pressure can be misleading if you have air in system in place of the Freon you need to keep the compressor from cycling.

Did you bleed the fill line when you filled it? If you do not, since it takes 3 fills, you could have air in the system.

Also, did you replace the accumulator? They needed to be done for many reasons when the lines are open.

Click to expand...

If he’s using actual gauges that have a high and low side, 65psi on both sides says 1 of 2 things

1. The compressor isn’t running
Or
2. The system is running but he has the gauge valves open instead of closed.

toomanytoys said:

The old one wasn’t clogged

Click to expand...

there’s only so many parts to an ac system,
Compressor
Condenser
Evaporator
Filter dryer
Accumulator / receiver
Metering device


You have a restriction on the high side that’s not letting the refrigerant get back to the compressor on the low side.

take a temp clamp and clamp it on the high side after the accumulator and filter dryer. There will be a temp DROP of about 5 degrees or more if there’s a restriction, check before and after the piece of equipment.

Should I jump the low pressure switch to keep the system running during this test?