Vintage Air Gen IV Problem- Blows Cold, Then Warm

[67ChevyRedneck]

I have an old sure fit system in my C10 that's been blowing Ice Cold since 2006.

I installed a new Gen IV sure fit system in my 65 Mustang with the electronic controls that's having issues. I have emailed V/A but haven't gotten a response, I will call them after I mess with it more this weekend.

Thought I would ask all the experts here to get some more input before I call them.

What's happening:

When the car is first started, the A/C runs/blows cold as it should. After 15 to 20 minutes of operation the compressor no longer cycles on and it blows warm air. The system was installed over a year ago and worked excellent until a couple weeks ago (but A/C has not been "run" since about October of Last year.) They system was evacuated by a shop for a full hour and held vacuum and they filled it for me.

If you turn the dial to "heat" for a minute or two, or turn it off for a few minutes, it will be cold again when you switch back to cold, or turn it back on.

Another weird issue... I never drilled a hole for the drain line. I've been using an old antifreeze jug with the hose going to it... when it's hot out, that thing would just about fill up with a few hours of use. I went to empty it and it was bone dry. I blew air up into the hose and everything sounds "loose/free" so it shouldn't be "plugged."

When it's not working I don't see any visible ice on any lines, there doesn't appear to be any oil at any fittings (no leaks?)

[k2rm]

Check for voltage at the pressure switch from the controls when you want the compressor running but it is not. If there is power then your controls are working. If there is no power from the pressure switch to the clutch, then either the pressure switch is bad or you don't have enough refrigerant. If there is power to the clutch but is not engaging, you may have a clutch issue.

[john]

If your evaporator coil is freezing up you will get the results you are describing. Can you see if they are frozen, looking through the vents?

[jhwkns]

Originally Posted by john

If your evaporator coil is freezing up you will get the results you are describing. Can you see if they are frozen, looking through the vents?

What John said^^

[Hart_Rod]

Originally Posted by jhwkns

what john said^^

+2

[67ChevyRedneck]

Originally Posted by k2rm

Check for voltage at the pressure switch from the controls when you want the compressor running but it is not. If there is power then your controls are working. If there is no power from the pressure switch to the clutch, then either the pressure switch is bad or you don't have enough refrigerant. If there is power to the clutch but is not engaging, you may have a clutch issue.

With the system off, there is 0 Volts to the compressor.

With the system working there is 13.2V to the compressor.

When it "stops working" there is about 3V to the compressor.

There was zero condensation in the "bucket" again. The line was completely dry. With the blower in high, I can feel a very light "breeze" almost like a gently breath coming from the drain tube, is that normal?

I couldn't see if the evaporator coil was freezing. I can check that tomorrow. What causes this, low refrigerant?

[screaminchevypickup]

Sounds like it's low on freon to me!! Are you running a binary or trinary switch?

Kyle

[67ChevyRedneck]

Binary.

[Andy4639]

Check the freon first for correct level all systems have the low freon switch to keep the compressor turned off if to low of freon to keep from burning up the compressor. That's why it will run long enough to realize it's low.

[67ChevyRedneck]

That's what I thought was happening, however I don't have a way to check it without taking it to a shop... trying to eliminate paying someone if possible. It held vacuum for an hour last year without budging the needle... if it is leaking I'm kinda pissed...

[Greenlee]

I installed one of these Vintage Air kits a few months ago. I was going to pay a shop to charge it, but ended up buying a set of gauges and vacuum pump off eBay. I watched a couple YouTube videos on how to check for vacuum and charge the system, and it turned out to be pretty easy. You could put some freon with dye in it to check for leaks.

The stand alone vacuum pumps are kind of expensive. The one I bought hooks up to an air compressor and was only about $15 to $20 if I remember correctly. However, it got the job done!

[67ChevyRedneck]

I thought about that too... Looks like a basic kit is only $40 or $50.

A couple have mentioned the switch going bad, which I don't think it is, because it's job is to reduce the voltage to the compressor when the pressure is wrong so it won't kick on, right, hence the 3 volts when it "wasn't working"? What volts would it have been reading *if it was* bad? 0?

I just redid everything under the hood too... installed a new export brace... I didn't mess with anything for the A/C though

[Andy4639]

Jess, I don't know what freon you used but...this would give you a idea on the level.

Go buy one of the cheap cans of freon at the parts store that has the gauge on it. It will give you a level without doing anything. If you used 134-A buy the artic freeze big blue bottle it's like $35.00 and it should fill your system up on the stang if it's completely empty. I use it in my truck and it works great. Very cold.
Say what you want about it but it has worked good for me. Just read the directions and understand them good before using it.

[67ChevyRedneck]

I don't have any problem filling it... but I don't want to fill it again. If it's not working, there's a problem?? (LEAK?!?!?)

The C10's system has never been touched and is ice cold, and it's been going for 8 years. I don't want to refill this thing every spring. I was crawling all over the car the past few weeks installing the new dual bowl power master cylinder and a full front suspension rebuild... maybe I moved or poked a pinhole in something?!?!?!

They both have R-134

I do have a gauge (the cheap one with the colors), I just have to find it. I took it to the place that did the work the first time (charged it) they remember my car, but were way too busy to look at it today. They had customer cars parked up in the grass.

[67 chevelle]

too much freon was stop it , too little freon will stop it , you need an ac guy to check your line pressures , if they are too low or too high , the trinary switch [usually mounted to the dryer ] will shut everything down , my very wild guess is you have a slow leak and low presure is kicking the system off, doing its job to save your system

a trinary switch example

Trinary Safety Switch Pressures:
LOW is OFF @ 28PSIG - ON @ 29PSIG
HIGH is OFF @ 454PSIG - ON @ 369PSIG
FAN - is ON @ 227PSIG - OFF @ 185 PSIG

from oldair

[67ChevyRedneck]

It has a binary switch, but same idea.

I did take it in at lunch, but they were busy. If there is a leak I want it found.

[Andy4639]

As stated hook the gauge up to it and see if it's low. I didn't say you had to fill it up. I sayed check it. This will give you at least a starting point. If you find the leak have it fixed then use the can of freon to fill it. It's cheaper than a shop doing it for you. You stated you didn't want to pay for it. Buy the gauge are find yours it's a quick look see.
Look for black oil on hoses and around the clutch on the compressor are buy a can of dye and put in it. Feel the hoses also to see if they are slick sometimes you want see the black residue if it's a small leak but everything will be slick from the oil.

[67ChevyRedneck]

Searched the car for leaks a few times now. Didn't see any residue. No oil. Everything looks clean and new. Put one of those cheap wal-mart gauges on it and it was on the high side of "charged area." I think the 34psi area.

Even when it's working it's peeing out ZERO water. This doesn't seem normal to me. Is it just not running long enough? This thing used to make a lot of pee water.

[litew8]

You could always buy a detector and check yourself.

[Andy4639]

Can you short out the compressor to make it run to see what the gauge reads like on a GM compressor. If so short it out long enough to see. You may have a bad switch to the compressor.
Sorry don't know much about Fords but all AC systems pretty much work the same.
Just a reminder if there isn't any cooling effect going on in the system it want pee anything so that is why the jug is empty.
Now to do some stuff on your own it's not free to work on cars and trucks as you well know.
But you can do it cheaper if you want to.
For
$35.00 worth of freon in the 1 can you maybe able to tell what the problem is. With the system off put the can of freon on it and shoot it into the system. Does it suck it right in with no problem, then most likely you have a leak you can stop here until you can find it. You can buy the bottle of dye to put in it also at this time to help find the leak. If it doesn't suck the freon in pretty good then crank it up and see if it can suck it in and after about a 1/4 of the can the ac should start working which will tell you what you want to know also. Then have it fixed. If it's not low on freon it want take much at all which will tell you that it's something broke are not getting signal.
Just my thought and how I did mine to find problems on the truck.
Man I can't believe I'm helping out a ford!


This is the switch on the Chevy AC you short the terminals and the clutch will run all the time.

[67ChevyRedneck]

My Car had 3 Problems:

1. Ford
2. Schrader vavle on low pressure side had slow leak, was down 0.35lbs (of 1.8).
3. Capacitors don't like water

So apparently I had a slow leak, I initially thought I did have a leak at the valve because of the oil build up I found in the cap.

On top of that, the capacitors were shot. I mentioned the "drip bucket" a few times above... my wife has knocked it over a couple of times getting water everywhere... which apparently included on my capacitors which are chillin' on the floor with the rest of the hoses and wiring...

[Andy4639]

Well I'm glad you figured it out finally!

[67ChevyRedneck]

Me too!