09 Prostar thermistor solution?

And use the heat shrink to both waterproof the connection to the thermistors and lock it in place as well. Did this April last year and the high side high pressure shutdown problem ended.

Also, on my 2011 Prostar, the original spec for freon was 3 pounds that was changed to 2.5 pounds last year.

Frank

 

I'm having my Thermisters replaced tomorrow. 2011 Prostar. It's hell on the road without AC.
And yes, 2.5 is the proper number/weight.

 

As a tech, I'd prefer if people didn't use those heat shrinks. Once you apply them there is nothing you can do to test there later on. It becomes a permanent connection that can't be opened with out damaging it. Heat shrink isn't 100% seal anyway. If you have a problem with the circuit and someone previously heat shrinked it, you have to cut the wires to test, and that is just dumb because you can still have a problem under the heat shrink. I recommend applying a dielectric grease to all electrical connections to prevent water intrusion. This way, you can easily disconnect, inspect and test at those connections.

 

AC still not blowing very cold. Just somewhat adequate. I guess I'll take it.
At least it isn't blowing hot anymore.

 

Ok, 09 Prostar will have lazy a/c for a couple different reasons. First, if the cab filter at the firewall, under the wiper cowl gets plugged, it will cause flow loss across the evaporator and lead to warmer a/c temps. Also, the kick panel right in front of the passenger seat, below the fuse/breaker cover is part of the blower housing. This panel is removed any time the blower is accessed or anything else in that area. It is really easy to reinstall and not get it perfectly aligned to the base housing. This causes air to leak around it which will cause major temp increases.

 

Thanks. Good to know.

 

I have an 09 Prostar - My AC runs decently cold for @ 15-20 mns and then starts to blow hot.
If i turn it off for 30-60 mins I can normally get cold air again.
Replaced, everything so far except the Evap Temp Sensor. Couldn't find it. I bought a new one, have the schematic and no one can find it. Dealer told me where it is, .... its not there.
and i don't even know if thats the issue.
any ideas on what the issue is or if its this sensor, where the hell is it?
OH and the sleeper is completely disconnected, rear blower doesn't work at all. have 2.5 lbs in system.

 

Out of the 3 threads that you posted your problem on you should read through this one carefully and follow the steps.

 

I think i did read through here, unless i missed something.
I have replaced the Thermostats also.
Im guessing that my AC is faulting out, because i have tried letting it run till it starts blowing hot, turn truck off for a minute or 2 and start it up again and i get cold.
being everything else is new, My next obvious question is, do I have to much Freon in the system and hence to much pressure??
Remember i have the sleeper completely disconnected, So its only the front , cab, that is connected and running
any one know what the correct amount (pounds) is for a day cab Prostar????

 

I have had a rash of bad new thermistors out of the box for about the last year. I have stopped buying them from dealer. MEI makes a good kit (#1400K) that I now use. For a quick test, unplug thermistors and stick 120 OHM resistors in place, and test. If you don't have a laptop, disconnect batteries for 10 min. to reset BCM.