Hello everyone, my ac has started giving me problems for about a week now. When I turn it on it works fine, then all of a sudden it stops getting cold. It still blows air but not cold air. If I play with the switch by turning it off and on it sometimes get it back working for a few minutes then shuts right off.


Also I would like to ask this without starting a new thread.
When I turn my truck on, it starts fine but after running for a few seconds it begins to idle down very low like its about to shut off but never does. The check engine light comes on and after driving it for a few it goes off. The check engine light also comes on while I'm driving it but goes off. I was thinking it was the distributor cap and rotor so I replaced it but I'm still having these problems.


Could someone help me out. ?

 

The blend door could be malfunctioning causing it to bring in outside air.


It's best if you can pull the codes on your truck so you don't waste time and money throwing parts at it.

 

Hey there, welcome to FTE.

Your a/c sounds like it's low on refrigerant. Probably a leak in one of the o-ring seals, or the compressor shaft seal. You'll need the correct (R134) service manifold to be able to check pressure (to be sure that it actually is low) and service the system properly, or if you're cheap you can get one of those all-in-one a/c recharge kits with the can, hose, and gauge, but these are a temporary fix at best and won't fix the cause of the problem. EDIT: verify a pressure problem by seeing if the compressor clutch (center of the compressor pulley) is disengaging whenever the a/c gets warm. If so then it's probably low on charge.

As for the check engine light and running like crap, you'll want to check the fault codes in the PCM (Powertrain Control Module, which is the computer that runs the engine and certain automatic transmissions). They'll point you to what the truck sees is wrong with itself, then it's up to you to figure out why (we'll help you). It's easy to do and requires no tools, just search on here for how to read OBD1 codes.

 

We put the ac recharge gauge on the system. It was a little low but we recharged it. It's still doing the same thing.
I took the truck to get the engine light to get scanned but everyone is saying they could only scan cars that are 1996 and newer.

 

That's why I said search on here for how to do it. I ain't gonna do ALL the easy work for ya...

If you don't want to do it manually (which consists of jumpering 2 pins under the hood and counting flashes on the check engine light) then you can spend a few bucks on this little goodie: and it'll do the job for you.

 

Also, 1996 was the year that OBD2 became mandatory on vehicles under a certain GVW. Some vehicles had it sooner than 96 and others (the ones that were exempt due to their weight) did not, for instance a 97 F-350 cannot be scanned by those types of places that offer to do it for free because they're OBD1 and require you to either use it manually by counting flashes, or you could use that reader I gave you a link to. Just some info in case you were interested.

 

Ok Dixie wasn't aware you could do it manually. Though it could only be read by a computer. But thanks for all the info

 

You're welcome. If you need help with it just come back and post the codes you got.

 

"When I turn my truck on, it starts fine but after running for a few seconds it begins to idle down very low like its about to shut off but never does." It is normal for your truck to idle down after start up but if the RPM's are too low, you might want to check your fault codes to see what the culprit is.

 

Warm up the truck then do this:
How to run a Self Test

Code Definitions:
3 Digit Codes

 

Hello, I'm getting throttle body sensor from the check engine light. Just would like to double check with you guys to make sure I did it correctly and if I'm not missing anything. Here is a link to a video took of it.
806B44DA-B797-47BF-8A51-B21B46D99366_zpsq16sfhyc.mp4 Video by ilovemymarine25-07 | Photobucket

 

Okay here's what I got:

KOEO:
121 (Closed throttle TPS voltage higher/lower than expected)

CM:
123 (TPS circuit intermittently above 4.5V)
124 (TPS sensor output higher than expected)
212 (Loss of IDM input to EEC or SPOUT circuit grounded)
452 (VSS/PSOM error in last 80 warmup cycles)

I would start by checking the TPS with a meter and verify it's output.

 

Ok i changed the tps, everything seems fine now so I guess that was it. Now I have to work on the Ac.
Thanks a lot.

 

Ok here is the latest and greatest info, truck was driving wonderful with the new tps sensor, now I'm having very high idles and when I put the truck into reverse it takes off like I'm pressing the gas? Check engine light has not been coming on. What do you think this is, idle control sensor?

 

Dump the codes again. Codes can be present even with no engine light.

Disconnect the IAC valve and see if it idles down. If so then the valve is fine and you don't have any vacuum leaks. Do this AFTER you get the current fault codes, because it might cause more.