Short Cycling

-
Ricks70Duster340

Ricks70Duster340

Child of the King
FABO Gold Member
Joined
Feb 8, 2021
Messages
1,340
Reaction score
1,059
Location
Sisterdale, TX
When I first start driving the Vintage Air system I have cools as expected. After about 30 minutes the compressor starts short cycling, whether I am stuck in traffic or driving on the highway. Just before it starts short cycling the compressor gets noisy when the clutch engages. Obviously when it short cycles it does not cool. I'm not an A/C guy so looking for some ideas what may be going on.
 
Check the duct temperature. It should not go below 40F. If it does, a block of ice will form on the evaporator restricting air flow and cycling the compressor on and off. This applies to high humidity conditions.
 
CUDA69 said:
Check the duct temperature. It should not go below 40F. If it does, a block of ice will form on the evaporator restricting air flow and cycling the compressor on and off. This applies to high humidity conditions.
Click to expand...
Temp starts out at about 42* when things are cool.
 
Check your water drain on the bottom. If a spider or bug makes a nest the water builds up on the coils and freezes. Make sure it is dribbling out water. If not a small amount of compressed air can clean it out.
Also- if your Freon is low from a leak- it will short cycle. Not enough pressure. When ambient temp it may be just enough to get it going but as it heats up and stuff expands there is not enough pressure to keep the compressor on.
Ac gauges need to be used to see if you have the proper pressures for the system.
 
Update: I attached some gauges and found the system was over charged. The tech at Vintage Air sent me a document showing the correct hi and lo pressures. I brought the pressure down to be within those ranges and the thermometer in the cabin vent went up. The VA tech said to bring the low side pressure down a bit more to see if that helps. If not, he said to clamp the water hoses going to the firewall to see if that helps. If it does he will work with me to determine why the heater control is allowing hot water to enter the cabin when the control is set to full cold.

Wondering now how to clamp those hoses without damaging them.
 
You must log in or register to reply here.
-

Back
Top