: 1975 Eldorado HVAC blower motor speed



john campbell
06-09-10, 03:43 PM
My '75 Eldorado has developed an HVAC problem. Regardless of how I set the Climate Control settings, the fan only blows on the lowest speed. Any suggestions of what the problem might be or how to track it down would be greatly appreciated.

John

77CDV
06-09-10, 06:36 PM
According the the FSM, it's either a back-out terminal or disconnet at the control head, or an open in the blower circuit wiring.

carnut
06-09-10, 10:23 PM
If its like the sedans and coupes in those years, then the hi fan relay has failed or the wiring connector to it has melted over time causing a poor connection to the relay. Without a service manual, I would guess its like the sedans and possibly located to the left of the steering column underdash in a bank of relays on a common black plastic board. look for evidence of melted plastic just below one of the relays.

pompste
06-17-10, 09:22 PM
My '75 Eldorado has developed an HVAC problem. Regardless of how I set the Climate Control settings, the fan only blows on the lowest speed. Any suggestions of what the problem might be or how to track it down would be greatly appreciated.

John

Hey John------did you ever get this problem solved? Check in and let us know. If you did get it solved---please post the fix.
I`ve got the same exact problem on my '78 Deville----fan only blows on the lowest speed.

john campbell
06-20-10, 06:44 PM
I'm afraid I've had several other vehicle repairs to take care of, and other things consuming my time unfortunately, so I haven't had a chance to get on this problem yet. But when I do, I'll definitely post the results. :)

ace1233
08-17-13, 06:09 PM
I seem to have to opposite problem....my fan only runs on HIGH....any thoughts

CADforce69
08-18-13, 08:28 AM
Maybe the blower relay is bad so circuit is closed all time. This would be the easiest cause. If itīs not this, it would be necessary to check the power servo or the main control unit.

ace1233
08-27-13, 09:29 PM
Thanks ....I will check it out and let you know. Appreciate this Forum....great to find a place to ask questions and get some real responses.