: heater fan acting up.. 80 cdv.



creeker
09-30-11, 03:36 PM
The heater fan motor on my 80 cdv. only works on defrost and bi-level settings, when I push lever to extreme right (defrost) it works on high
speed,and bi-level only works on low fan when moving lever to the left, if I slide lever to the right to bi level it does not work, I can also hear air
(vacuum line?) when I move lever around, the fan itself sounds fine, anyone have any suggestions.

The Ape Man
10-01-11, 06:00 AM
Pull the climate control head out of the dash. Look for melted connections in the female electrical socket and burned traces on the circuit board.

creeker
10-01-11, 12:07 PM
Pull the climate control head out of the dash. Look for melted connections in the female electrical socket and burned traces on the circuit board.


Thanks can I remove it from front of dashboard, (rather than going in behind).

carnut
10-01-11, 09:38 PM
Remove the radio bezel then the climate control head is removed from the front of the dash. The large gauge orange wire usually melts where it plugs onto the connector to the head. It also melts at its other end in the multi relay panel under the steering column. Sometimes you can cut this wire out of the connector at the control head, clean the brass connection and add a new connector. At the relay end, again sometimes you can remove the wires that go to the hi speed relay in the multi wire relay center and install new connectors and let the relay dangle out of the panel. The defrost mode bypasses all the automatic fan speeds in the control head and usually continues to work.

The Ape Man
10-02-11, 10:31 AM
Above agrees with my experience.

It helps to know the right way to remove the radio bezel. Let us know if it gives you trouble.

drmenard
10-02-11, 11:37 AM
Before you start pulling your dash apart check this first... There is a temp sensor that turns on the blower motor and the blower will only work on defrost or A/C untill the motor warms up a bit..If this sounds like what your car is doing, look for the sensor, its on the passanger side motor head near #1 spark plug... You should see only one wire there connected to a small temp sensor.. Pull the wire off and ground it.. If the blower goes on, thats your problem.. Sometime they are hard to find and guys just leave it grounded and don't have the warm-up delay..

creeker
10-02-11, 01:11 PM
Before you start pulling your dash apart check this first... There is a temp sensor that turns on the blower motor and the blower will only work on defrost or A/C untill the motor warms up a bit..If this sounds like what your car is doing, look for the sensor, its on the passanger side motor head near #1 spark plug... You should see only one wire there connected to a small temp sensor.. Pull the wire off and ground it.. If the blower goes on, thats your problem.. Sometime they are hard to find and guys just leave it grounded and don't have the warm-up delay..

Is that the wire that also controls the "hot temp. warning" light as well, I know where that one is. Thanks everyone for the great explanations.

drmenard
10-02-11, 03:02 PM
No it is not the same sensor...BUT the two look the same, you can only tell them apart by the number stamped on them.. the number is the temp that they switch on... When you find the sensor on the passanger head for the heater blower, on the drivers side head , in the same place is the over temp sensor... thats on the back of the head for the over temp sensor...

The Ape Man
10-02-11, 04:23 PM
That's right about the block temp sensor too : )

I've had to ground every one in every Cadillac I ever owned. Been so long I completely forgot. Good catch.

creeker
10-02-11, 04:54 PM
No it is not the same sensor...BUT the two look the same, you can only tell them apart by the number stamped on them.. the number is the temp that they switch on... When you find the sensor on the passanger head for the heater blower, on the drivers side head , in the same place is the over temp sensor... thats on the back of the head for the over temp sensor...

So then there are two sensors doing two separate things?, (I know where they are located), one is for temp warning light and the other one is heater control sensor, my
temp. hot light kept coming on when the engine was not hot, I disconnected both sensors quite awhaile ago because I thought they both did the same job, Thank you.

The Ape Man
10-02-11, 05:35 PM
Yes there are 2 sensors. You may have created the blower in-op condition. If your HVAC block sensor still works I'd be surprised though.

creeker
10-02-11, 05:43 PM
[QUOTE=drmenard;2732609]Before you start pulling your dash apart check this first... There is a temp sensor that turns on the blower motor and the blower will only work on defrost or A/C untill the motor warms up a bit..If this sounds like what your car is doing, look for the sensor, its on the passanger side motor head near #1 spark plug... You should see only one wire there connected to a small temp sensor.. Pull the wire off and ground it.. If the blower goes on, thats your problem.. Sometime they are hard to find and guys just leave it grounded,

creeker
10-02-11, 05:50 PM
Before you start pulling your dash apart check this first... There is a temp sensor that turns on the blower motor and the blower will only work on defrost or A/C untill the motor warms up a bit..If this sounds like what your car is doing, look for the sensor, its on the passanger side motor head near #1 spark plug... You should see only one wire there connected to a small temp sensor.. Pull the wire off and ground it.. If the blower goes on, thats your problem.. Sometime they are hard to find and guys just leave it grounded and don't have the warm-up delay..

Happy days!!, I grounded out the wire as you suggested and the fan works fine now,thanks a lot for the help.

creeker
10-02-11, 05:51 PM
[QUOTE=drmenard;2732609]Before you start pulling your dash apart check this first... There is a temp sensor that turns on the blower motor and the blower will only work on defrost or A/C untill the motor warms up a bit..If this sounds like what your car is doing, look for the sensor, its on the passanger side motor head near #1 spark plug... You should see only one wire there connected to a small temp sensor.. Pull the wire off and ground it.. If the blower goes on, thats your problem.. Sometime they are hard to find and guys just leave it grounded,

I resent this thread by mistake.