PRESSURE AND TEMP
List 4 things that will make both high and low side pressures go up.
1. Air in the system
2.Over charged system
3.Too much oil in the system
4.Restricted air flow across the condenser
What can make a blower motor slow down.
A resistor.
What electrical component controls the doors in the evaporator case?
ELECTRIC MOTOR (blend, mode, distribution)
What is the refrigerant that was phased out by 1996?
R 12
What tools can you use to find leaks?
1.dye
2. soap and water
3. visual
4.electronic leak detectors
5. vacuum
What can make both high side and low side gauges read low?
A system that is under charged.
Some _______ _____ may turn on even if the keys are out of the ignition.
Cooling fans.
What door in the case controls the temperature of the air?
The blend door.
What is the refrigerant used from 1996 to the present?
R 134a
How can you tell if a thermostat is not working correctly?
1. over heats
2. over cools.
What two natural things can have a effect on pressures in the system.
1. Ambient temperature
2. humidity
Use caution around blower motor resistors because they can become very_____.
HOT.
What door in the case controls the intake of the air?
Fresh air door.
What refrigerant needs up to ten times the working pressure to work?
R 744
What tool can we use to tell what is in the ac system?
Refrigerant identifier.
What component in a ac system heats up the refrigerant heat up?
The compressor.
What will happen to a compressor clutch if it get a low voltage?
1. May not engage
2. May slip
What door in the case controls the delivery of the air?
Mode doors.
What is the new refrigerant used in todays cars?
R1234yf
What does oil on a line tell us?
There is a leak.
What ac component causes the refrigerant to cool down?
The metering device ( fixed orifice tube, txv)
What is a nc pressure switch?
closed during normal conditions.
Any of the doors in the case may be controlled by any of the following three ways.
1.vacuum
2. cable
3. electric
What should we do with unknown refrigerant?
Treat it as if it is contaminated.
What test do you need to have the car set to ac max and up to 1500 rpm,s?
A performance test.