73 Fleetwood ATC Blower problem

[Lars Kneller 8246]

I have a 73 Fleetwood 75 and the front climate control blower isn't working correctly.  It will blow low when set on VENT and high when set on DEFROST, but otherwise does not work.  Occasionally when I am driving along it will start working when set on AUTO but the blower speed is erratic.  I have been through the system a couple times and cannot seem to pinpoint the problem.  Any suggestions?  Thanks.

[cadillactim]

Lars

Sounds like the programmer is going bad.  It controls the blower when in AUTO.  Can you control the temperature, get cool air on 65 and hot air on 85?  If not, or works intermittently, I would suspect the programmer.  I sell them reconditioned for $100 with exchange.  If you want one you can email me directly at tagroves@wctel.net, or call me at 864-348-3209 (eastern time zone).  Tim

[Lars Kneller 8246]

It does change temperature like it should.  I did put in a different programmer out of one of my parts cars and it didn't make a difference.  I guess that doesn't necessarily mean the other one is good. I have one other used one I can try and if that doesn't work, then I'll get one of your rebuilt ones.

[TJ Hopland]

Sounds like the temp switch thats on the front corner of the head.  I think its on the corner of the right head sort of behind the alternator.  The other side has one that looks the same but has a differnt temp setting because it is for the engine temp light on the dash.  Its around a 3/4" nut with a single tab connector.  When the head gets to a certain temp the switch closes and grounds the wire to tell the controler that the engine is hot and it then kicks the fan on, that way you dont get cold air blowing while you are waiting for the engine to warm up.   The reason it works on vent is the fan always runs on vent and it works on defrost because thats a safety issue if your windows were fogged up.  Check and see if the wire has just come off or been damaged, if it looks ok make a jumper wire and hook it to ground and see if the fan works, that will tell you that the wire and control/relay works.  IF thats all good its possible that the switch is bad or that someone installed the wrong switch.   The heater one turns on at like 125* and the other one at 265* or something like that so you see why it wouldnt work if they were wrong.   The sensors dont go into the coolant so you dont have to worry about loosing coolant or sealing them if you replace one.   On my car I just hooked the wire to the alternator bracket because its a convert that I never fixed the AC in and rarely need the heat but at least the fan will run now if I need it.

I have a 73 shop manual around somewhere if we need to dig further.

[greg surfas]

I have a 73 Fleetwood 75 and the front climate control blower isn't working correctly.  It will blow low when set on VENT and high when set on DEFROST, but otherwise does not work.  Occasionally when I am driving along it will start working when set on AUTO but the blower speed is erratic.  I have been through the system a couple times and cannot seem to pinpoint the problem.  Any suggestions?  Thanks.
Lars, Check the blower relays on the firwall.  Check the connections and check to see that they are functioning.
Let me know