Well, I have done a search through old posts and the archives and have come up with a couple of different solutions, but would like to know the best place to start. The truck is a '95 F-150 4x4 XLT, regular cab, long box. Has the 302 and Auto w/OD tranny. I have owned the truck for about 2 years and it has 129,000 miles on it. Just this year the A/C has decided to work when it feels like it.

When you first start the truck, you can run the A/C on Norm or MAX and it will blow COLD. As soon as the truck comes up to operating temperature, the A/C will stop working. Park, let truck sit a little bit, start back up in this warm weather and A/C will not work. Let sit for a couple hours to completely cool off, start up, and A/C will work until truck is back up to operating temp.

Any idea on where to start? Don't want to fork over a fortune in diagnostics when I can try and solve on my own. Recharge? Vacuum problem? Any thoughts would be appreciated. And I did notice the other night it seemed like the Defrost was not working very well - windows getting fogged up very easily and only clearing in patches.

Sorry for the long post, but now that I have decided to keep the truck, there are a couple of thing I would like to get fixed.

Thanks,

 

I don't know about your ac but I've got an explanation for your defogger. It's all tied to your ac problem. Your ac is what helps your windows to defog by removing moisture from the air.

 

That is what I figured. The A/C engages with the Defroster to help take mosture out of the vehicle, right? And since the A/C is not working right, it can not defrost properly. And that will become quite important this winter in Iowa.

 

A couple ideas.

1 You may be low on refrigerant. There is a switch on the AC system that shuts down the clutch in the compressor if it detects low refrigerant. You may be borderline and just triping the switch when warmed up. When your AC is on and NOT working, does the compressor pulley clutch engage? I. E. is the middle of the pulley turning along with the outside of the pulley. If the clutch is not engaged, then I would suspect low refrigerant. You can buy a guage that can help you determine this.

Another area that happens to me, almost every time I mess with the engine on the AC handler(The big box in the engine bay against the fire wall where all the AC hoses go into), my AC will shut down and a lot of times I will light up the check engine light. There are some plastic vacumm lines that go into some rubber connectors, and it is very easy to cause the connector to unplug while moving your hands around in that area. A lot of times the plug will look like it is plugged in but actually isn't, You must check it by hand. A easy, free fix, but doesn't quite sound like your problem.

Good Luck,

Jim Henderson

 

Well, I checked today, with the A/C switch in the Norm or Max spots, the belt it turning just fine, but the center portion of the A/C part is not turning. So, I assume the compressor is not engaging. Hence, my lack of cold air and lack of defrosting ability.

With a truck of this age ('95) and miles (129,000) would the freon level be the first place to start? And I am assuming the tag on the truck is right that it does have R-134?

Thanks,

 

Sounds like you need to visit a reputable air conditioning shop. They will be able to fix you right up. The coolent and compressor lubrication travel around the system together. If you are low on coolent you are probably low on lube as well. The coolent doesn't just get low or wear out. A leak usually causes this so the shop may have to replace seals too. Any time one opens up the system a couple other parts also need to be replaced before the system is recharged. Just recharging the system will probably get you cold air for a while, but if the leak is not found and fixed you will be right back here soon.

Ask around. Find a good shop. A lot of places do not have the equipment or experience to do a good job.

 

I did call around to a couple of places today to get diagnositic prices. Best I found was Car X which wanted $39.95 + freon and dye to test. Then any seals, replacement parts, etc would of course be extra with labor. They and the other shops I called said the same thing: A/C systems are sealed systems that do not just "loose" freon. If it is low on freon, there is a reason.

And I did find a coupon for $29.95 for the A/C check. Thinking I should probably just go ahead and schedule it in there to at least find out the cause of the low freon is and to get it recharged properly.

 

My 94 F250 had your problem a couple years back. It only had maybe 50,000 on it but the coolant was low. The good news is, that even the 94 had R134, which is much cheaper tha the old stuff.

I didn't have the gear to do it right myself so I took it to the dealer. they charged $90 for a refill and added flourescent dye to check for leaks.

My guess is that since I live where it isn't really hot and I only drive maybe 5,000 per year now, that the AC seals may have leaked a bit. This is a reminder that you should use your AC/Defrost at least once a month for several minutes, to circulate the lubricants and keep the seals soft.

Other recommendation, which I always forget because I am in a rush and it is so hard to find competant mechanics where I live, is to go to a good independent shop specializing in AC. They will probably be cheaper and do a better job than a dealer.

Note that R12(?) the old stuff can costs hundreds for a refill. That stuff is something like $20(?) per 1 pound can.

Good Luck,

Jim Henderson