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Discussion Starter #1
My dads 1994 aerostar is giving him issues with the A/C. He uses it as a work vehicle (panel van style) and uses it daily with no working A/C (90*+ temps outside)

It blows warm/hot air through the vents so he went and bought the do it yourself kits to re-charge the A/C. He charged up the system as best as to what he knows how to as it was his first time trying. And it still blows hot air.....now he was messing with a plug that controls the a/c compressor and when he unplugged it to check the connection and plugged it back in it blew the 20amp fuse under the dash. And has blown several fuses since then messing around with it. Still no cool air and the compressor will turn on for only maybe 30 seconds after putting a new fuse in and then it blows the new fuse.

His system seems to be holding the freon or whatever it may be it just doesn't seem to be pumping it through the system and into the van.

I know absolutly nothing about A/C units so if someone could guide me into trouble shooting this issue that would be great. I feel sorry for my old man having to drive with no A/C and this summer heat. He really can't afford to take it in and have a shop charge him for their service.
 

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Perhaps it has too much freon? I know one time my friends car was doing this. It showed full of freon and wouldn't cool. What we did was on the low pressure side where you fill it up with freon, we pushed the little valve with a standard screw driver while the compressor was on, making it release some of the freon, after that it started to cool.
 

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Discussion Starter #3
We've tried to let some of the pressure out while the engine was running but not yet while the compressor is going.

Our issue with that is that the everytime the compressor turns on it blows the fuse in the fuse panel for the A/C compressor. its a 20amp fuse.
 

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What plug was he messing with? The one on the compressor or the one on the accumulator, which is a pressure switch. Was the clutch on the compressor engaged before he put the charge in? Will the clutch engage before it blows the fuse?

Blows fuse:
Wireing shorted ? Unplug from compressor-turn on A/C-check for 12VDC at plug.
Compressor clutch shorted out.
Compressor clutch not engaging. ie:pulls high current,blows fuse.
The freon charge if too high will not blow fuses, but will make V-belts slip.

This may help.
 

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ac compressor relay...famous on the chebby's. Should be on one of the inner fenderwells if I remember right. The relay is drawing too many amps. costs about 10 bucks.
 

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double post
 

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If I recall, coolant flows through the heater core all of the time and there's a damper door to divert air around it when not using heat. That damper door is driven by a vacuum motor; there might be a leak in either the motor or the tubing powering it.

How hot is "hot"? You didn't say whether the hot air it's blowing is at radiator temperature or at outdoor air temperature. That could make a difference in where to look for the problem.
 

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Discussion Starter #9
I would say its 80-95* air that its blowing. So that would be par with outside temps.

The plug we have pulled to check connection (which is when all the fuse blowing started) was on the accumulator. (I believe it was the accumulator) the black bottle that actually has a site glass on the top? you can see bubbles flowing past it when we were filling it.
 

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lee--when the bubbles disappear--its full--and--the compressor--if it blows the fuse--is probably going south--tooooo much drag from int damage---when a system loses freon--it normally loses oil with it--and after so many refills--no oil left---gooodbye comp-----
 

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[ QUOTE ]
... if [the compressor] blows the fuse--is probably going south--tooooo much drag from int damage ...

[/ QUOTE ]

True for electrically-driven compressors. Not true for belt-driven automotive compressors. They don't draw more current when the compressor gets worn out and the drag increases, because they only use electricity to pull in the clutch, not to turn the compressor.
 

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Hello, When A system is overcharged it will have a symptom Known as Floodback. It will start to ice up the suction line from evap back to compressor. And will still cool.On a comercial or residential unit. But on your van You might have a Expasion valve problem. Some thing stuck in it like a minute piece metal or slag. or you valves are shot in The compressor. Did you convert to R-134A or is it R-12? 1994 should have been R-134A. You can jump out the pressure control to engage clutch, But you better have a set of guages on it. then you can see what the compressor is doing. and see what pressure is. 35Psi on low side should yield a 40* evap coil. also remember Temperature and Pressure are directly Proportionate. If temp is up pressure is also. never the oppsite. And the condensiong coil when vehicle idle draws heat and then the fans come on. Fords were notorious for O-ring Problems. I had to replace on my 93 Lightning. Hope this help sorry for being long winded.
John
 

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[ QUOTE ]
[ QUOTE ]
... if [the compressor] blows the fuse--is probably going south--tooooo much drag from int damage ...

[/ QUOTE ]

True for electrically-driven compressors. Not true for belt-driven automotive compressors. They don't draw more current when the compressor gets worn out and the drag increases, because they only use electricity to pull in the clutch, not to turn the compressor.

[/ QUOTE ]

The lack of oil from the escaping freon is still true though and is likely candidate for a dead compressor. Perhaps the heat from the dying compressor overheated the coils in the clutch and they shorted making them draw too much current and blow the fuse.
 

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LOl or you could all be wrong we've bought a lot of vehicles where we thought the A/C was bad cause it blew hot and full on r-134a and compressor not leaking but think simple before hard, alot of times the hot to cold knob for the ac controls gets warn bad and you may have it set on hot but the control is not moving the temperature. Had this happen on a lot of fords....
 

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yeah... except he's blowing a fuse, so it doesn't really have to do with freon at this point. Who knows what caused it to get that way....

If you really wanted to test though you could turn the air on and feel some lines under the hood and see if some are getting cold and others hot.
 

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On my old work truck(a chebby)it did that with me and it was the low pressure switch,and until they got me a new one the quick fix was tap it with something metallic(back side of a knife blade for me)and it kicked right on.I don't know if your dad,s van has one but it's just a suggestion.
 
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