I took off the vent actuator and repaired the gear that was split causing the clicking sound. Before putting it on I tested it to be sure the actuator turned both ways. I put 12v on one pin and ground on the other and then reversed to spin the other way. All good. I then connected the wire and tested the recirc button. It closed the vent when lit and when I clicked the button again it did not open the vent as it should have. I tested the switch and it gets 12 volts when pressed and lit and 0 volts when pressed again and not lit. My question is, and I tried to find wiring diagrams, shouldn't the switch reverse polarity to get the actuator to open in the opposite direction? If there are only 2 wires, +12 and ground, how would the actuator go in both directions. Is the switch faulty?
Joey

 

Looking.....what year?

 

I'm sorry, I forgot to add that. 1998 SL2.

 

I looked up for a 2000. Both have a BCM so close enough.

Schematic below is from 2000

Recirc control circuit,


The polarity switch across the motor is done inside the HVAC controller itself per vehicle schematic. One side gets voltage while the other is grounded. 12 volt drop in One direction across the motor, and then 12v drop in the other direction. Monitoring only at the motor, you would see, without moving your probes, 12 volts, then - 12 volts if everything is functioning properly.

However in your case it sounds as though there is an issue with the controller since the polarity switching occurs inside the controller.

 

Thanks for that information. It is what I thought as when the recirc led was illuminated I saw 12 volts. When the I switched the other direction, I saw 0 volts instead of seeing -12 across the terminals. So I need an HVAC control head. I have found a few on ebay as they do not make them anymore.
Thanks,
Joey