Any tips for troubleshooting/diagnostic heating system?

[Anton CH.]

My passenger heat does not work. I already replaced the heater valve (broke it during a cleaning procedure). I am pretty sure my aux water pump is not fuctioning (pluged it in, put the car in run position, didn't spin) but I doubt that is causing the problem as the driver heat is working. What should I check next?

[Anton CH.]

Anyone?

[winfred]

it's easy to test the motor, connect a hot and a ground and it will run, generally if the motor is not working if you get any heat you are lucky, the cooling system just doesn't supply enough pressure to circulate the coolent through the extensive amount of plumbing, it will follow the path of least resistance

[Anton CH.]

Is the aux motor meant to be always on when the car is in run position or only when the car warms up? As I said, the way I tested it: pluged the motor into the plug, put the car in run position, nothing spun. I get a good amount of heat by using the driver heat and the face vents.