Hello everbody, I hope someone can help me out.
I have a '99 Ranger 4x4 Super Cab with a 4.0/5speed. It seems like my a/c isn't working very well. I checked the charge and it's in spec and all the fan speeds work, but it seems like there isn't much air moving through the vents nor is it particularly cold. It will cool the truck eventually, but it takes a good 15-20 minutes in 90 degree weather. I've also noticed it works better at highway speeds than in traffic.
Is all this normal?
Hartski

 

If you develop a vac leak by default the air will blow out the defrost vents. Is that what is happening? Are you using max a/c to initially cool it down? You might have a bad hot water shutoff valve or vac leak at the valve. It shuts off flow of coolant to heater core when a/c is engaged. It will cool down quicker at highway speeds due to more air passing over condenser and a/c compressor running at a faster RPM.

 

Thanks for the tips 03. I'm using max a/c all the time. I'll check to see if I'm getting airflow out of the defroster vents and see if I can't find the hot water shut off valve.
If I have some sort of vacuum leak will my "check engine" light come on?
Hartski

 

Depends on the location and size of the vacuum leak.

Check your radiator and condenser for any buildup of "crap" on or between them. Reduced airflow through the condenser from either obstruction or inadequate fan speed is a common reason for your symptom.

 

The "not particularly cold" could be from the blend door issue that plaques these trucks (and many others) with factory A/C. If the blend door isn't directing the full air flow thru the evaporator, the air will never be as cool as it should be. Even worse, if the heater valve isn't closing like it should.....

 

Thought of that and forgot to mention about the blend door. Also check the temp of both freon lines going into cabin. One should be hot the other should be cold to the touch and generally sweating from the temp difference. If not you have a freon flow or weak compressor in spite of a full charge. Did you hook up a gauge set to both the low and high side of a/c system to check the readings? Only checking the low side (where you charge) doesn't tell the whole picture of how system is functioning. The hot water shut off is near firewall where hoses pass into the cabin to hook up to heater core. Just follow the heater hoses and look for it. Will have a vac line attached to it. Also check that either fan clutch for radiator fan or electric fan (both pull air through condensor in front of radiator) is working properly when a/c is turned on. My 03 has an electric fan for pulling air through a/c condensor. Your 99 may use just the radiator fan.

 

I appreciate all the input fellas, but I'm afraid it's a moot point now.
Saturday afternoon I crossed a set of RR tracks that were much rougher than I was aware of. The truck lurched sideways into the gravel, fishtailed back and forth across the pavement before spinning 180 degrees, catching air, and rolling three times down a steep embankment. I finally came to rest with my undercarriage up against a tree.
Every window was shattered, I climbed out the passenger window, up the embankment, and spent Saturday nite in the Trauma Center.
The truck is completely destroyed. I still don't know how I walked away from it with little more than a few scalp lacerations and overall soreness. I'll try to post a pic when I get some.
Hartski

 

Sorry to hear of your accident, but glad to hear you are alright.

 

The lower the fan speed the less amount of heat can be extracted from the refrigerant during cooling mode. The process of air conditioning is heat extracted from the air. In residential and commercial hvac systems there is a control board or fan relays or both that determine the fan speed for which call. Cooling is always in high speed (or a higher speed) and heating in much lower speed. On a vehicle, I'm not sure how that works as you have a fan control on the dash. In other words if your fan was by chance starting to go out and was running lower than it should have than that could have very well been the problem.

I'm a residential and commercial hvac (air conditioning) technician.

Sorry to hear about your truck.

 

Btw, the high pressure high temperature discharge line is the hot line. The return low pressure low temperature line is the cold one and is the one where your condensation that drips under your vehicles comes from.

 

'99....

You need to check and be sure your condensor is not clogged with debris and make sure the condensor/radiator cooling fan(s) are in good working order, running at full high speed with the compressor clutch engaged. Also, if the engine coolant "tends" toward overheating the compressor clutch will get disabled until the coolant temperature declines back don to "normal".

With the engine driven fan it's probably beyond the time to replace the fan's VC coupling.