A/C works, but output is low

johnwartjr

Registered User
95 SC, bone stock

The A/C works, and blows cold. The levels of refrigerant are fine.

Blower motor is recently replaced.

The AC output isn't as strong as I remember it being in years past.

The output is proportionate as I turn the dial on the dash - meaning the 'maximum' is higher than the 'minimum', but the maximum just seems kinda low.

Any ideas where to look? Likely culprits?
 
Check your condensor make sure it's clean & clear. Do you have the air dam installed or not missing? Your system might be clogging your orface tube causing reduced flow.
 
Check your condensor make sure it's clean & clear. Do you have the air dam installed or not missing? Your system might be clogging your orface tube causing reduced flow.

Condenser is the miniature radiator looking thing in front of the radiator, right? Is it something I can clean out without pulling the front bumper off?

The air dam on my car is pretty torn up, held in place with a series of zip ties etc. I might be able to remove it and rebuild it using fiberglass or some sort of epoxy.

My car also starts to heat up when it sits for long periods of time with the air running. I have a new water pump, but have not installed it yet. Wonder if that is contributing? It's fine if the car is moving, but when I sit in a parking lot with the air running for 10 minutes or so, it creeps up til the 'check gauge' light comes on. Water pump doesn't leak or make noise, so I've not gotten around to installing it yet.

Radiator is a year old and aluminum, system was flushed when I installed it.
 
Yes, you can clean the condesor at the car wash, run at A/C while cleaning with the wash wand & see if your air temps inside are colder,if so then your on to the problem. Due to the cooling problems I did the Alum. Radiator Napa cooling fan motor & new condensor & a grand-prix air dam. The OEM fan motors are weak a new motor will help, I am going to get a Fan assy after market for the SC from ebay motors for my 95 & see how it works.

You can go to home Depot & get a roof corner trough 2'' for 4.xx & cut it to length & slice a split on 1 side to make it taper to the bumper & some sheet metal screws or double sticky tape & go drive. Make sure you also have the air guide on the top between the head lights & along the hood latch & slider release.
 
Thanks, have a few things to look into, it seems.

The radiator fan motor is a year old. Works well, but I will have to verify that it is on when the A/C is on.

I also have a sticky relay that sometimes leaves the fan on when the car is stopped. Need to repair that too.

The joys of a 17 year old car, pity Ford hasn't made anything I'd want to replace it with :)
 
Yup, it should be on all the time the a/c is on when you are less than 45mph.

Fraser



Fraser, should the pusher fan (front side of car) be operational at all times when the A/C is turned on? From what I understand this fan came on the 94-95 supercoupes.
 
Yes the 94/95 came with the additional "pusher" fan .. but regardless of what year you have, the Radiator fan should come on with the AC on max.

The AC on Maximum recirculates the Cabin air. ( this is the most efficient setting ) Anything else, will pull air from the outside.

You said your refrigerant levels are OK - how do you know ? Did you have the system evacuated and re-filled ? What are your pressures with the AC on ( High and Low side ) .. if you have about 30-40 psi on the low and 170-250 psi on the high would be good. I dont know how you charged it .. if you just used cans and didnt vacuum the system to 29.5 HG's .. you may have other issues like moisture in the system, I dont know what you did.

I would check the condensor for obstructions first, but I doubt this is causing your AC to run hot unless you have a big plastic bag covering it up.

Your Radiator running hot could also have an effect on the condensor ..

What are your AC pressures running at ?


- Dan
 
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So should the pusher fan stay on all the time with the A/C?

Sorry, not to hijack, well, I suppose it's related.


Yes the 94/95 came with the additional "pusher" fan .. but regardless of what year you have, the Radiator fan should come on with the AC on max.

The AC on Maximum recirculates the Cabin air. ( this is the most efficient setting ) Anything else, will pull air from the outside.

You said your refrigerant levels are OK - how do you know ? Did you have the system evacuated and re-filled ? What are your pressures with the AC on ( High and Low side ) .. if you have about 30-40 psi on the low and 170-250 psi on the high would be good.

I would check the condensor for obstructions first, but I doubt this is causing your AC to run hot unless you have a big plastic bag covering it up.

Your Radiator running hot could also have an effect on the condensor ..

What are your AC pressures running at ?


- Dan
 
The pusher comes on at 220+ I have never had it activate & hope not to. It only came on for me when I did a KOER test (94/95). It (push fan) does not come on with the A/C, but the Hi speed circuit on the Radiator fan comes on with any A/C or defrost, DEF/FLOR selected.
 
He says the A/C is cold but the flow is low----I'm taking that to mean the flow from the vents inside the car is low and the only thing that could do that is blockage of the evaporator....I'm thinking mice nests or wasp nests inside the heater/A/c housing.........Dan
 
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He says the A/C is cold but the flow is low----I'm taking that to mean the flow from the vents inside the car is low and the only thing that could do that is blockage of the evaporator....I'm thinking mice nests or wasp nests inside the heater/A/c housing.........Dan

Yep.
Obstruction OR blend doors OR the fan resistor-relay-thing is not running the fan as high as it should be.

I have one that runs on high alllllll the time.
One that must be blowing behind the dash because some of the vents blow good, others not.
One that I have to slam the glove box door at times to make come back on.

If his radiator fans were not running the ac would go hot cold hot cold because of extreme pressure/heat on the condensor. Not the case. It a volume thing is sounds to me.
 
Just an update from today's driving trip...

I noticed that if I put it on AC (not MAX), it blows hard. Put it on max, the output drops significantly.

So, when it's using outside air, the output is strong. Recirculating inside air, the output is weak.

Is the blend door perhaps stuck closed? Where does it 'pull' the inside air to recirculate from? Logic (which doesn't always work!) says it's having a hard time 'breathing'?
 
Well, it had to get as hot as all get out for me to dig deeper and find the solution.

While sitting in a parking lot, waiting on my wife, and sweating, I got on my smartphone and started googling the problem I was having.

I found this thread:

http://www.sccoa.com/forums/showthread.php?t=110065

and sure enough, it was the culprit! A plastic sack from the grocery store was stuck where the system was trying to suck in cabin air to recirculate.

Pulled it out, have nice cold hard blowing A/C again!

Wah00!
 
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