no indeed it doesnt have anything to do with it. you see the ac heater has diffrent conections in where the theremostat has nothing to do with if u were talking with temperature changes maybe it would.
Check the thermostat.
First place to look is the thermostat
The AC switch operates the AC compressor and should have no bearing on your heater function. If your heater is not working properly, you may have a weak thermostat.
That or the thermostat.
It matters if it has ac or not. If it is a non ac vehicle, the hoses and coolant flow from the fitting close to the thermostat housing to the lower heater core tube, then out the upper heater core tube to the fitting on the water pump. If it has ac, the hose from the upper heater core tube connects to the fitting on the radiator.
To troubleshoot issues with your AC and heater system, check the thermostat settings, replace air filters, inspect the circuit breaker, clean the condenser unit, and schedule regular maintenance with a professional technician.
The heater core is usually your last resort. So now start from the end to the beginning, core, thermostat, flush, hose, fluids. Follow the trail and your bound to find your answer.
the thermostat used to control the heater and after we select the four pole switch to some number the thermostat start connect the power to the heater at the same time the heater start to heat and when we select the switch to zero position the heater not work
If both the AC and heater are coming on at the same time, it could be due to a malfunction in the thermostat or HVAC system. This issue can occur if the thermostat is set to "auto" mode, causing it to activate both the heating and cooling systems simultaneously. It's best to have a professional HVAC technician inspect and repair the system to ensure it is functioning properly.
An AC water heater can be converted to operate on DC current but the cost will be large. In the electrical trade anything can be done if enough money is spent to get the results that are requested.
To fix the AC and heater on an Aerostar van, first check the fuse related to the HVAC system and replace it if blown. Inspect the AC compressor for proper operation and ensure the refrigerant levels are adequate; recharge if necessary. For the heater, verify that the thermostat is functioning, the coolant level is sufficient, and check for any blockages in the heater core. If issues persist, it may be necessary to consult a professional mechanic for further diagnosis and repair.
The thermostat could be stuck closed. the heater core could also be plugged or the door closes when you use ac and opens when you use the heater may not operate.