F250 ac

[Stmar]

I have a 1996 F250 that I use sparingly, 460 so it guzzles gas and I want to preserve it for pulling/heavy work. I thought the AC was out, it blew not so cool air, not hot but more like regular vent air. I use it around the place so it may be 5 minutes use at a time. Had to drive it about 20 miles today and after about 5 miles it started cooling down and eventually was working?? Got to where I was going, stayed about 20 minutes and when I left it did the same thing, 5 miles down the road it started working good again. Stopped again and same thing. Any ideas of where to start looking for the problem?

 

[CaveCreekRay]

Two "totally out of you-know-where" suggestions to start with...

1. Is your compressor clutch engaging right away? Start the truck up AC-OFF. Let it stabilize for a minute and then kick the AC on. Can you sense the engine slow a tad? Have somebody switch it on while your head is near the compressor... do you hear it click on and does the pulley look like its rotating the compressor???

2. Any evidence of contamination on the fan clutch? A leaky seal on the compressor can leak freon and lube out on the backside of the compressor clutch which may contaminate the clutch enough to prevent engagement until it heats up a little... Any leaks under the compressor? Stick a clean folded paper towel there and check it the next morning. If you find the compressor pully oily, you may be able to get it working by degreasing the pulley/clutch but, it will probably require service soon by an AC specialist as it will need lube and more freon.

3. There may be a one-way check valve in your system that opens under operation and its sticking. Not sure where that would be.

Let us know what you find out!!!

 

[Stmar]

Thanks, will try and check those possibilities out. Have not noticed any leaks but will double check in the morning, too hot right now, lol. Probably needs an expert service but I hardly use it so no hurry.

 

[Tooljunkie]

A tad low on freon is my guess, but it could be leaking out as described.

 

[Stmar]

Never had the Freon checked so that is a possibility. Looks like I have a few things to check out. Thanks for all the input.

 

[CaveCreekRay]

Seals dry out if you don't "use" them frequently. A small leak from your compressor could have started over winter when you used the defrost mode (AC) and you might have lost most of your charge before summer arrived.

Even on cold days, I try and remember to crank on the AC three or four times through winter. Same with the heater in summer. Its nice to get some water flowing and valves valving in between being left in one position all the time. Circulating water through your heater core is a good idea even in summer, every now and then.

 

[scdeerslayer]

Check the condenser for dirt/debris, and make sure the fan is working.

Circulating water through your heater core is a good idea even in summer, every now and then.

The older vehicles that I've gotten deep into circulate water through the heater core 100% of the time, and just blow air over the core when you turn the heat on. I've had to work on them because the heater core would be leaking, often in the summer. Are newer vehicles different?

 

[CaveCreekRay]

I don't think that is quite right...

My '99 4Runner has a temp knob that controls hot water access to the core. Turn it cold and run the fan and its cold. Select hot and its hot. If it was hot all the time, it would counteract your AC chiller. If your core gets hot all the time, your temp select valve is toast. You should not have a hot heater core when its selected cold.

Every car I have worked on or owned only has one fan for both AC and heat.

 

[Racer X]

First, the AC cycles all the time, even when the driver has not selected AC. All newer vehicles have this feature designed onto them to keep the refrigerant and the lube circulating in the system, and to remove moisture, even in winter months.

Second, as an older vehicle sits, the refrigerant seeps out over time, and every now and then needs replaced. This is something you can do yourself. Go to a quality automotive parts store and get the small refrigerant refill can and the hose to use for putting in into the system (some come with the hose already attached, I don't care for them, as they often are poor quality and leak).

Third, make sure the condenser is clear from bugs and debris. If it is dirty the air cannot efficiently remove the heat as the refrigerant passe through it. Also keep in mind that the system relies on air passing through the condenser to work well. When the vehicle is stationary, or moving slowly, not enough air moves through it to effectively cool the refrigerant before it passes back to the evaporator. This is why it seems to work better on longer drives.

 

[CaveCreekRay]

Interesting...

I'd bet lunch his 21 year old truck doesn't auto cycle. My 18 year-old 528 doesn't. Neither does my 19 year-old 4Runner. When the AC switch is off, you don't get AC except when selecting defrost mode.

Newer cars? I'll tell you in a year or two! LOL....

 

[Racer X]

Interesting...

I'd bet lunch his 21 year old truck doesn't auto cycle. My 18 year-old 528 doesn't. Neither does my 19 year-old 4Runner. When the AC switch is off, you don't get AC except when selecting defrost mode.

Newer cars? I'll tell you in a year or two! LOL....

Even when the AC is not switched on by the dash control, the clutch still cycles on and off while the engine is running.

 

[Tooljunkie]

Fords have been cycling the ac for many years. Most ac systems will run the compressor while on defrost. (Defog)

 

[Stmar]

The plot thickens. Now remember that I do not use this truck very much at all, it probably has been off the place and driven more than 20 minutes a time no more than a few times over the last 5 years and for a while the AC has not worked very good. Yesterday was my day of discovery where it worked after driving certain distances as I stated in my earlier post. Today I go out to see if the clutch is activating and it starts getting cold immediately, cold air coming out and the freon tubing under the hood gets very cold. Could it still be low on freon or could it have been from inactivity and things are lubed/limbered up now?

 

[Racer X]

The plot thickens. Now remember that I do not use this truck very much at all, it probably has been off the place and driven more than 20 minutes a time no more than a few times over the last 5 years and for a while the AC has not worked very good. Yesterday was my day of discovery where it worked after driving certain distances as I stated in my earlier post. Today I go out to see if the clutch is activating and it starts getting cold immediately, cold air coming out and the freon tubing under the hood gets very cold. Could it still be low on freon or could it have been from inactivity and things are lubed/limbered up now?

If it functions as expected why mess with it?

 

[Stmar]

If it functions as expected why mess with it?

You are right, I tend to screw things up trying to make them better. Probably should just make it a point to take it out more often and blow out the gunk. Most of the time it gets used in the winter pulling my 8Ns out of snow banks and busting snow drifts so hopefully I have that issue taken care of with my 4wd Kubota.

 

[Racer X]

You are right, I tend to screw things up trying to make them better. Probably should just make it a point to take it out more often and blow out the gunk. Most of the time it gets used in the winter pulling my 8Ns out of snow banks and busting snow drifts so hopefully I have that issue taken care of with my 4wd Kubota.

There ya go.

 

[CaveCreekRay]

There you go. Must be a Ford-ism. That should help with their CAFE standards. No wonder their new pickups shut off at long stop lights: They have to save that energy to periodically run the AC!

-Buddy just bought a F-150 with the EcoTech and the sales guy told him that vehicle has 24 computers on board. He over-rode the shutdown mode because it delayed launching in hot weather. Do they put bigger starters on those things? Can't think a regular one would last...

 

[Racer X]

Do they put bigger starters on those things? Can't think a regular one would last...

Reduction gear starter drive.

 

[Ridger]

Could it be the blend air actuator? My 2005 GMC 2500 will often blow warm on driver side and cold on passenger side. If I turn the engine off and restart it will usually correct itself.

 

[Tooljunkie]

My new (to me) 93 chevy a/c wasnt working. So i grabbed a can of r-12 substitute and proceeded to juice it up. Not even 1/2 a can and it started cycling. Sorta. After a period of inactivity, the clutch wasnt engaging properly. Ran it for 1/2 hour and now it seems to work fine. Not bad for 550,000 km's on the clock.
The oils settle and things probably need to work a while to sort themselves.