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roybelding
roybelding, Shop Foreman Freightliner trucks
Category: Medium and Heavy Trucks
Satisfied Customers: 5714
Experience:  Shop Froeman for Freightliner Trucks
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I have a 24ft box truck freightliner m2 buss class that the

Customer Question

i have a 24ft box truck freightliner m2 buss class that the a/c clutch wont stay engaged it cycles on and off
Submitted: 2 years ago.
Category: Medium and Heavy Trucks
Expert:  roybelding replied 2 years ago.
good afternoon my name is ***** ***** I will assist
most likely the freon level is low. a low pressure switch in the system turns the compressor on and off based on low side pressure. when the pressure drops below 20 lbs, the compressor cuts off until the pressure gets above 20 lbs. this usually happens with low freon level. there may be a leak in the system. the system should have a dye added and run and inspected for the leak. then it can be repaired and re filled with freon
Roy
Customer: replied 2 years ago.
Have sister truck right beside truck took all parts off working truck put on none working truck truck has proper freon level in sometime is cutting compressor off
Expert:  roybelding replied 2 years ago.
how much freon did you add?? did you vacuum the system prior to charging??
is it blowing cold air???
Roy
Customer: replied 2 years ago.
Pulled freon out to see amount freon was correct 2lb 14 ounces vacuumed down recharged checked power to compressor losing power
Expert:  roybelding replied 2 years ago.
ok, is the air cold??
when the ac is working properly. the compressor will cut out when the low side goes below 20 lbs
do you have a gauge set to monitor the pressures and verify the pressure and the cut out???
you may also have a bad low pressure switch. watching the pressures will help tell us what is going on
Roy
Customer: replied 2 years ago.
Ac clutch never rims lone enoght
Expert:  roybelding replied 2 years ago.
ok, can you use a voltmeter and monitor the voltage ???
Customer: replied 2 years ago.
Yes
Expert:  roybelding replied 2 years ago.
good, check the voltage and be sure there is a constant 12 volts at the clutch.
also, check the low pressure switch on both sides for the same voltage
Roy
Customer: replied 2 years ago.
Have voltage at low pressure switch and compressor 13.2 at both if I unplug low pressure switch voltage goes away at compressor plug back up voltage comes back and stayes
Expert:  roybelding replied 2 years ago.
ok, if you have 13.2 at the clutch of the compressor constant then you either have a bad ground on the wires or a bad clutch in the compressor
Roy

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