AC alternating hot and cold


TheCitrusMaster

New member
Joined
Nov 27, 2018
Messages
23
Reaction score
1
Points
3
Location
Euless, Texas
Vehicle Year
2000
Make / Model
Ford
Transmission
Automatic
Ok, so my 2000 Mazda b3000 started doing this about a month ago and I feel it is slowly getting worse. I am thinking it is probably just low on refrigerant but I haven't checked. Before I fill it up or take it to a shop I wanted some other opinions on the matter.
1: When I start the truck AC always blows cold. When it does blow cold, it is ICE cold, which is awesome. It will stop after about 15 minutes or so, and then alternate hot and cold every 5 minutes or so.
2: If I turn off the ac for a few minutes it always blows cold when I turn it on again.
3: When the AC gets warm, it isn't hot, just warm (like the outside air). It is also very sticky/moist/humid which feels HORRIBLE in the 100 degree heat. I read this can happen if it ices up due to low Freon.
4: I dont know for certain, but I think I hear and feel the AC compressor clutch disengaging when the air starts to blow warm. I read it can do this if it is low on Freon.
Other info: I have a brand new fan clutch (it went out and I was having overheating issues, fan clutch fixed the issue) and also it is hot as hell in Texas so the alternating AC issue is very annoying :/

PS: My mom has a 98 Jeep TJ 2.5 and the AC compressor locked up just a week ago, I rerouted the belt but its going to need fixed at some point. Also my sisters car isn't blowing very cold anymore, just somewhat "cool" *sigh* seems everyone is having AC issues.
 


Rock Auto 5% Discount Code: 173A8B749AB83C Expires: January 1, 2020

TheCitrusMaster

New member
Joined
Nov 27, 2018
Messages
23
Reaction score
1
Points
3
Location
Euless, Texas
Vehicle Year
2000
Make / Model
Ford
Transmission
Automatic
It seems I still have the overheating issue, as it began to overheat again today in traffic. It is better than before, but still not fixed.
 

RonD

Well-known member
Joined
Jun 2, 2012
Messages
13,745
Reaction score
529
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
All AC systems work by compressing a liquid and then letting it expand.
How much it expands is how much it cools
When you get low on the liquid then it can expand more, but............that cools too much and you get freezing temps in the evaporator(in the heater/fan box), and low pressure switch opens and cuts off compressor so it doesn't "run dry".

So yes, you most likely are low on liquid, if it feels VERY COLD when its working

Bad fan clutch will cause a rise in temp when stopped or driving slowly, that's when the fan is needed, when driving above 30mph the air flow thru the grill is enough to cool rad, worn out water pump impeller can show up as this as well

If temp goes up above 30mph then its not fan clutch, most likely radiator has blocked passages, or you have a leak that is allowing air into the system
Keep an eye on Reservoir tank and check rad level when engine is cold, should be at the very very top, no air at all in radiator, if there is air then you have a problem with reservoir system or a leak
 


Top