75 CDV ambient temperature sensor

[jaydog]

Mechanic says mine is out of range and is why the AC blower goes on and off.  It is located in the blower housing.  Anyone with a source for a new one?

[Scot Minesinger]

Cadillac Tim in Iva SC, he is very reasonable.  That might not be it, but for the cost, it may be worth a try. 

These are resistors that pride a resistance of say 50 ohms or whatever.  Two wires touching are zero ohms, and two wires apart are infinite ohms.  To test this theory of a bad sensor, unplug it and that will be infinite ohms the blower should operate continuously on high or be on off/real low. Then jump it with a "paper clip" and the fan should operate on high of very low/off.  If nothing happens either way it is not the sensor.  Obviously check it for damage, but have never seen one fail in two dozen climate control repairs - any that were bad is because they cannot survive a screw thru them or a fierce hammer blow.

Many times the fan not running is the temp switch behind alternator.  This switch makes ground at 140'F or so.  unplug it and ground the spade and if fan runs, that is your issue.  I routinely ground these as it is most common fan failure cause.  Purpose is so when it is real code out fan does start until engine is warmed up so no cold air blows on ankles - we drive in warm weather generally, so who cares.

Good luck

[jaydog]

Thanks