Dash air cut off on 02 Winnebago

[Oldwirehead]

Has anyone be able to disconnect the blower fan cut off from the AC compressor cutout switch? If would to know how.

[BFlinn181]

Since the fan operates when set on Heat and fresh air, I don't think it's wired through the low pressure cut off switch.

[Johndale]

Originally Posted by BFlinn181

Since the fan operates when set on Heat and fresh air, I don't think it's wired through the low pressure cut off switch.

X2
The fan is not tied to the ac pressure switch. ? Why do you want to unhook the fan? You can pull the fuse or unplug it from the blower. But need more info on what you are trying to do.

[Oldwirehead]

Talked to Winnebago Tech and he checked and said the blower fan was wired in with the AC low pressure cut off switch. So when the RV is under a load with the AC on the compressor will cutout, which is fine, but I don't want the blower fan cutting out.

[Johndale]

Originally Posted by Oldwirehead

Talked to Winnebago Tech and he checked and said the blower fan was wired in with the AC low pressure cut off switch. So when the RV is under a load with the AC on the compressor will cutout, which is fine, but I don't want the blower fan cutting out.

Evans Tempcon, Inc - Technical Support
Ok if you look at the wiring for Evans if that is the system you have the high pressure controls the Condenser fan not the Evaporator fan. The Evaporator fan will run all the time the system is on. I hope this link helps you

[BFlinn181]

We've got a confusion of fans. I thought you were referring to the fan under the dash that blows through the vents into the cab. There could very likely be an electric fan(s) that blow across the condenser. If the condenser is inline with the radiator, an electric fan may come on when the compressor is running to continue to disperse collected heat while stopped at a light. If the condenser is off the the side, there again may be one or more fans that come on with the compressor.

The compressor comes on when the thermostat on the HVAC control calls for it. First the electricity passes to the low pressure switch to be sure there's enough refrigerant in the system to operate. That power then goes to the electric clutch on the compressor and to the electric fans. There may be a relay involved to handle high amperage.

Some systems also have a control that shuts down the compressor when the engine is under heavy load to give more HP to the wheels. This can be controlled by a mechanical or vacuum control on the engine, or in newer vehicles the ECU shuts off the compressor under high demand for HP.

None of the systems I'm acquainted with shut down the dash fan due to refrigerant pressure. If that were so, you couldn't defrost the windshield or use the heater if dependent on the pressure in the A/C system.

[Oldwirehead]

It seems he heater/AC fan is not stopping, but the air is being routed to the defrosters when the motor is under is under load. Was told this could be is vacuum leak. Any idea where to start looking? Any help will be greatly appreciated.

[BFlinn181]

If all air flow is diverted to the defrost vents, that is definitely a lack of vacuum. It's the default setting so windshield can be cleared. To find a vacuum leak, you need to start at the engine intake manifold and trace the hoses. A spray can of carb cleaner can help find leaks, while engine is idling, a squirt of carb cleaner on a leaking joint will increase idle RPM momentarily. If you don't find a leak under the hood or dog house, move to under the dash.

[Johndale]

I found 2 leaks on mine. The line to the max air door was full of micro holes. Cut out the part in the engine compartment and use black vacuum hose to slide over the blue hose I think it is 1/4 inch. And 2 at the bottom right side you have the main vacuum accumulator and the main feed line was rotted. It is only a couple of inches long but when you touch it you will know. Mine was like it melted.