Compressor cycling fix
#21
Master FORD tech
I'm all for improving our truck, but this is one hack I'd stay far away from. That sensor is made to cycle off the compressor at 37 degrees. Those that are saying the compressor is cycling off at a higher temperature I'd think there's another issue, like Rnlcomp said "low freon charge". An evaporator temperature at 37 degrees should produce 40 degree panel temp.
SO HACK AT YOUR OWN RISK!
SO HACK AT YOUR OWN RISK!
The following 4 users liked this post by Hotcat:
#22
I'm gonna go ahead and let ya'll try this out, and after it passes a long term test i'll give it a go. With a new compressor around $300, I dont wanna toast mine after a few months of cooler air
#23
Senior Member
This pic out of the service manual applies to 2010 only, but if you get the manual for your year truck, it would not be difficult to check if you have a switch that is out of spec.
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digitaltrucker (09-04-2014)
#24
Member
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Last edited by RLXXI; 09-02-2014 at 09:23 PM.
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digitaltrucker (09-04-2014)
#25
evap sensor
Does ford sell a sensor. No. You have to buy the whole unit. Mine cycles every 9 seconds. The cycle rate should be about 50- 60 seconds to have a vent temp of 40 degrees. Anyone else cycle rates like mine?
The following 2 users liked this post by Bigdog364:
digitaltrucker (09-04-2014),
Green Gem (09-04-2014)
#26
2013, same thing. About every 9-10 seconds. I am lucky to get to 45
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#29
PLATINUM
Admittedly a novice with A/C systems, but I have had issues with the a/c in almost every vehicle I have ever owned. In every case of my a/c not cooling like I wanted it to and the compressor cutting on in short intervals the refrigerant levels were low...2 cents...
In any case I hope this is a miracle cure for the not so awesome a/c these trucks have.
In any case I hope this is a miracle cure for the not so awesome a/c these trucks have.
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scap99 (09-02-2014)
#30
Master FORD tech
The 04-08 F150s the sensor pokes through the a/c. On the 09-14, Ford switch to a sensor that is probed directly between the evaporator fins. They both use the same sensor connector and on the newer sensor the plastic plug that holds the connector on is the same hole the older sensor screws into. So technically you can plug the old style sensor into your truck. The reason Ford switched to the newer sensor was to get a more accurate reading to prevent evaporator core icing. Using the older sensor would be a safer way to get false readings, or hack so to speak.
I have replaced several fleet/off road f150 hvac cases for dust buildup behind the evaporator core blocking the sensor, usually causing the system to cycle short. This was a pain to diagnose because there was good air flow through the ac ducts(normally there is reduced flow when the core is blocked). I even took the old hvac case apart just to see how it was possible that there was good flow but a false reading on the sensor. Sure enough, the dust buildup was thicker right on the other side of where the sensor is probed. Letting the air flow around it but not through it causing the compressor to cycle short. It's been awhile since I actually diagnosed one, if it's a dusty work truck and everything else checks out, it gets a case. These trucks were on the severe side of dust and it didn't help that Ford set the ac to default to freshair. So when these drivers are around on the dirt roads with their ac blasting on fresh air it doesn't take long to effect the readings of the sensor. This is why after I replace those case assemblies I get permission from the fleet managers to unplug the fresh air/recirc door actuator leaving the door stuck on recirc/max ac.
There's an idea, if you wanna mod your ac in a safe way, UNPLUG YOUR FRESHAIR ACTUATOR.
I have replaced several fleet/off road f150 hvac cases for dust buildup behind the evaporator core blocking the sensor, usually causing the system to cycle short. This was a pain to diagnose because there was good air flow through the ac ducts(normally there is reduced flow when the core is blocked). I even took the old hvac case apart just to see how it was possible that there was good flow but a false reading on the sensor. Sure enough, the dust buildup was thicker right on the other side of where the sensor is probed. Letting the air flow around it but not through it causing the compressor to cycle short. It's been awhile since I actually diagnosed one, if it's a dusty work truck and everything else checks out, it gets a case. These trucks were on the severe side of dust and it didn't help that Ford set the ac to default to freshair. So when these drivers are around on the dirt roads with their ac blasting on fresh air it doesn't take long to effect the readings of the sensor. This is why after I replace those case assemblies I get permission from the fleet managers to unplug the fresh air/recirc door actuator leaving the door stuck on recirc/max ac.
There's an idea, if you wanna mod your ac in a safe way, UNPLUG YOUR FRESHAIR ACTUATOR.
The following 5 users liked this post by Hotcat:
Alwaysaford (06-11-2018),
Daniejw (05-14-2016),
digitaltrucker (09-04-2014),
Green Gem (09-04-2014),
Walt2137 (07-18-2015)