A buddy of mine has a `72 GS with a fan problem.The fan will work on all settings except Max.Just wondering anyone has an idea what the possible problem might be? Also when the fan is on no air blows through the dash vents,is there a vacuum switch or door in the heater box not working? Any input appreciated...........Thanks,Jeff
blower relay could be bad or not getting juice through its "big" wire. my first suspect might be the blower relay that is mounted near the blower. cars use a SPDT relay that when "resting" allows current from the switch (on all but high speed) to pass through the relay to the blower motor. when you click the switch on the highest speed, that relay removes the blower motor from the regular circuit and connects it to the battery directly for maxximum speed. even if the relay "clicks" dont mean its making contact inside.
Check the vacuum cannister on the firewall. This happend to me where the A/C would only blow by my feet (no vents). Turns out that this vacuum tube was disconnected (thanks to Carl Rychlik for finding it so easy).
