01-19-2017, 07:05 AM
That microswitch on my 93 also energizes the opening of a solenoid valve at the inlet to electric coolant circulating pump.
If the fans are running, even if the coolant pump isn't running you should get at least a little heat coming through because the engine coolant pump is operating unless something is getting in the way of the flow. One way to check this out is to get the engine warm, turn on the heat control, go to the engine compartment and feel the heater hose starting from the shutoff valve on the engine (remember there are two valves, on for the feed and one for the return). If the hose isn't pretty warm, make sure the valves on the engine are open, then check that the pump is running and solenoid valve, if equipped with one, are open and running. Basically, you are verifying the flow of hot coolant through the heater core. If I had to make a wild guess at the moment I would guess the shutoff valves at the engine got closed somewhere along the line of messing with the dash heating and cooling.
If the fans are running, even if the coolant pump isn't running you should get at least a little heat coming through because the engine coolant pump is operating unless something is getting in the way of the flow. One way to check this out is to get the engine warm, turn on the heat control, go to the engine compartment and feel the heater hose starting from the shutoff valve on the engine (remember there are two valves, on for the feed and one for the return). If the hose isn't pretty warm, make sure the valves on the engine are open, then check that the pump is running and solenoid valve, if equipped with one, are open and running. Basically, you are verifying the flow of hot coolant through the heater core. If I had to make a wild guess at the moment I would guess the shutoff valves at the engine got closed somewhere along the line of messing with the dash heating and cooling.
Jon Kabbe
1993 coach 337 with Civic towed