09 prostar a/c replaced everything still not working

The engine fan is controlled by the engine. The a/c is controlled by the cab computer. When the cab computer wants the engine fan to come on because the a/c pressure is high it will send a message to the engine computer to turn on the fan. Sometimes if the engine computer or the cab computer have be reprogrammed or had their software updated the parameter can get turned off that allows the engine to listen to the cab computer. If this is the case, then the "Fan Override" switch also won't work, (if it has one). This parameter is on the Cummins side. You would need Insite Pro to be able to view and change this. It would be under 1939 multiplexing.

 

Blower motor working now. But a/C won't cool now. Low pressure stays around 25 no matter what.

 

I have the same problem on my 09 ProStar. The AC runs for 15 minutes after key on then the compressor shuts off. The engine fan will not cycle. It just runs constantly. I just had the body controller software updated yesterday but no codes showing. They did not even check the thermistors or high pressure sensors. Can I buy the parts and have Petro or TA draw down the system and put them in or will they need Diamond Logic to do it?

 

The high pressure sensor you can change yourself because there is a schrader valve for that. The thermistors do require the system to be drawn down to replace. All three sensors are just plug and play, no need for Diamond logic. You can unplug them and see if there is only corrosion in the pins. The thermistor pins are really tiny and connectors smalls, so be careful.

 

Okay so I am stumped. I watched The videos by Rawze and read all that I can find and I still can't quite figure this out. I have a 10 prostar and a/c issues. I burned the comp. clutch up on Friday which put me without cold air. I changed the clutch and it started blowing cold again. I left Saturday morning and it blew for an hour and quit blowing cold. I thought maybe it was low even though the clutch was still engaging so I put in some refrigerant. It blew colder than it ever had before for most of the day, then quit again about 1600 yesterday and nothing I try can make it fire back up. The clutch engages, but blows hot air. I checked both thermistors and the bottom one reads 2500 ohms and the top one 1500(I hope I am saying that right) which should mean they are both good according to Rawzes videos. I checked the pressure switch and it shows current so that should be fine. I can find no leaks. I put one of those parts house can gauges on it and it read less than 15psi when clutch was engaged and about 55 when stopped. So put another can in it until it was at 30psi while clutch spun. Still nothing. I hear a bit of a hissing sound from the neighborhood of the dryer/evaporator, but can't quite locate its specifc origin, but it just sounds like a normal a/c sound. I pulled the cabin air filter and felt the evaporator and it's no colder than ambient temp. The small line from the dryer is getting hot like I think it's meant to and all of the other lines from the expansion valve are ambient temp as well. I am afraid to keep putting refrigerant in it because I found an international check sheet online last night that may suggest(if I read it correctly) that I may be overcharging it. As I have never noticed a leak before, I can't image it is that low and 24oz later I'm afraid I'm going to pop the safety valve on the compressor. I don't have 1500 dollars to throw at snotty shops that want to just replace everything so I am hoping for some help ASAP. Please??!!

 

You can test a lot without having the right tools, but you can't check everything. When the a/c compressor is still engaged, if the system is working the inlet line to the compressor should be cold, outlet line hot, lines at the firewall coming out of the evaporator should be cold and the system making water if it is humid out. If the air vent temp is warm, but the lines are nice and cold you have a blend door problem, (temp door). The bunk should be cold though. If the lines are warm/hot, not cold and the compressor is engaged, you have a very low charge, expansion valve is stuck open, or the compressor is not internally pumping. If the system works awesome, then quits all of a sudden, then you turn the key off, restart and retry, then it works awesome again for a short time, this is normally an electrical problem and the body controller is sensing a fault and shuts down the a/c until the next key cycle. Usually the high pressure sensor is the culprit as once one of the thermistors goes, it stays faulty until the system cools down or warms up fully again. The capacity of your system is 3 pounds, or 48 oz. If you have put in another 24oz chances are it is way overcharged at this point. I understand your frustration with dealers. I hope you understand they are not all the same. Since the a/c system is computer controlled, you need to connect Diamond Logic Builder software to it to see what is going on, what the computer is reading for temps and pressure. You will now also need someone with an a/c machine to properly charge this. Since the compressor clutch burnt up and all you changed was the clutch, the rest of the compressor is now suspect for heat damage. A/c compressors do not like to run hot for too long. The cool refrigerant returning to the compressor is what cools it. If the charge is too low or too high the returning refrigerant is warm or hot and therefore not cooling the compressor. It won't be long before that compressor fails. To get the best service and have this fixed right, you need to find someone who is good with Prostar wiring, knows how to use Diamond Logic Builder software, (computers) and also knows a/c. This is where it goes bad as not every tech is knowledgeable in all these areas, and therefore why repairs have to be repeated. I know this is not your fault, but this is something you need to demand when you visit a repair shop.

 

Got one for ya Heavy.

Had/have an A/C problem.
This is weird, A/C blows fine. Then the cruise randomly shuts off. Blower still blow but comp stops. Same time the cruise shuts off, the Jake's and air horn no longer work. When driving, turn signal will shut off cruise. Cycling key off then back on while rolling, resets the cruise to be operational again. When parked, cruise won't stay on for idle up. If cruise not on, A/C won't work.
2010 Prostar ISX
ave already spent 1,000 this week. . When cruise is operarational, A/C works great. Replaced comp, dryer, high switch, and both therms.
What the hell is going on. Have had truck 4weeks. Former Knight truck. Have 2 others with no issue.
That's about it.
Checked the ECU wire connection at battery, good and clean.
Thanks for any help

 

The harness that runs along side of the steering column for your steering wheel switches and turn signal has been known to rub and short out on the column down where it pivots. The a/c wires do not run in this harness, so the a/c working only when the cruise is on is mostly likely something to do with body controller. International did not give the wiring or connectors enough room around the body controller and it is common to find harness too tight and actually pulling the connector side ways on the body controller enough to break the mother board inside! Try to adjust your steering wheel position, this will wiggle the harness next to it and maybe change the problem. Then you can remove the kick panel to the left of the clutch pedal to expose the body controller and try wiggling the harnesses and connectors to see if that does anything. Road test it with the panel off to see if anything changes.

 

Heavyd I have a problem that it could use some help with. At times my break lights will not work, when this happens you can press the break pedel and not hear the relay click in the fuse panel. When they are not working you can turn on the four ways with the break pedal depressed and the break lights will start working again. Also when they are not working and you depress the break pedal the traction control light will come on on the dash. I have taken the truck to the dealer and they seem to have no idea as to where to start. Going back to them tomorrow to try again.

 

Do you have Prostar, or 9000 series?