Since it is finally air conditioning time in Buffalo, its time to learn how the system works on my 1982 300 SD.

Currently, when the AC is engaged, it blows cool (compressor comes on and cool air comes from vents) for awhile, then the cool gives away to heat sent straight from Hades.

On investigation, I have discovered that my aux fan is not running (tight until i manually forced a revolution, and now spins freely). I have power at the relay next to the drivers headlamp connection, but no fan activity.

Any ideas? I am prepared to simply recharge the system and replace the aux fan, but ..... if there is more at issue, I would like to resolve those issues first!

Come on up, the sailings fine on Lake Erie and Ontario