• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

A/C blowing hot with R-134a charge


ranger hans

New Member
Joined
Jun 12, 2015
Messages
2
Reaction score
0
Points
0
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
I've got a 1988 Ranger with the 2.9 V6. My problem is that my A/C is blowing hot air, but there is a charge of R-134a in the system (it was converted many years ago and has worked on and off since).

The compressor was replaced about 3 years ago and I believe a few other components are new to system as well, circa 3 years ago. The compressor is turning (not just the flywheel, but the compressed clutch is engaging), but the air coming from the vents isn't getting cold. I know that freon is circulating because when I put a gauge on the low pressure side, it would jump from high to low as the compressor cut on.

My first thought is a bad expansion valve but wanted to run this by you guys to see if anyone else has had experience and wisdom to share.
 


Rock Auto 5% Discount Code: 70D65189E6D8FF: January 5th, 2022

cvar

Member
Joined
Apr 27, 2012
Messages
588
Reaction score
19
Points
18
Vehicle Year
1997
Make / Model
Mazda
Engine Size
4.0L V6
Transmission
Automatic
What are your high & low side pressures? Ambient (outdoors) temperature too? And how often does the compressor cycle on & off?

Dropping low-side pressure when the compressor kicks in suggests that it's trying to draw r134a by suction, but it doesn't mean it's actually flowing as it should be, esp. if the orifice tube is blocked. And are you low on refrigerant?
 

f3joel

New Member
Joined
Jun 2, 2015
Messages
18
Reaction score
0
Points
0
Vehicle Year
1991
Make / Model
Ford
Transmission
Automatic
Might need to adjust air gap on the compressor clutch.
 

adsm08

Senior Master Grease Monkey
Supporting Member
Article Contributor
Ford Technician
TRS 20th Anniversary
Joined
Sep 20, 2009
Messages
34,623
Reaction score
3,566
Points
113
Location
Dillsburg PA
Vehicle Year
1987
Make / Model
Ford
Engine Type
4.0 V6
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Tire Size
31X10.50X15
You can't tell anything by the low side pressure alone, and just going by pressures isn't that accurate a way to say if the system is fully charged or not. You need to evacuate the system and see what is recovered.

Unless you have access to actual AC equipment air conditioner repairs are best left to a shop.
 

kimcrwbr1

Well-Known Member
Joined
Dec 6, 2009
Messages
6,044
Reaction score
42
Points
48
Location
maplevalley WA
Vehicle Year
1983
Make / Model
ford
Engine Size
2.8l
Transmission
Automatic
The only way to know what is going on is by hooking up a set of guages. You can try adding refrigerant if it is cycling on and off rapidly that is normally the low pressure cutout.
Just use the delta temps inside. Put the A/C on max and measure the temp under the dash center mast and the air out temp. You want to see at least 20 degrees difference. Just add a little refrigerant first off and see if it starts to take longer between cycles. If not you need a set of guages to see if it is going high pressure on the liquid side. Was the work done to it done correct? was it pressure tested? Was it evacuated properly? If there was water in the system when the refrigerant was added you likely need a new compressor, orifice, suction line filter and a complete flush to remove any acid in the system.
 

ranger hans

New Member
Joined
Jun 12, 2015
Messages
2
Reaction score
0
Points
0
Vehicle Year
1988
Make / Model
Ford
Transmission
Manual
Thank you all for the advice! Sounds like I may just need to take it to a shop. I don't have much by way of AC equipment at the house.
 


Top