I have a "99" crown Vic that has a blower fan glitch. It will only run on high and medium low. It blows in all postions it just will not change speeds except for the two I mentioned. I have changed the blower motor and switch to no avail. When I use a jumper wire on the harnes at the switch it works correctly in all positions so I replaced the switch with a second "new" switch. Still only two speeds. Any ideas? [/align]

 

Blower resistor, or if it is EATC the blower controller

 

Thanks for the reply. However, we changed the blower motorwhich would include the resistor as well as the fan control. As I indicated, if we jump the wires at the control plug it works. As soon as we plug the control switch in I am down to two speeds.We tried two new controls adn they are working or not working the same.....only two speeds

 

The resistor is not part of the blower motor, are you saying you replaced both?

 

Yup....Change it all. Initially changed the resistor and the plug to it on the harness because it melted. Then changed the blower motor and thecontrol. My first thought was wire harness but when youunplug the control and jumper the wires all speeds function correctly. That is why I tried a second control thinking the firstone was faulty. I don't have a clue!!

 

Not sure if you got it fixed but you can run a self test on the eatc To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.
and let me know i 'll tell you what to do to exit the test press the blue(cooler) button and you keep the dtc's in memory but if you want to erase the codes press the defrost button .

 

Thanks b rabbit, however, thisunit does not have theelectronic controls, all manual. No, still can't locater the problem. This is a department car and I can only they are considering replacing it (car) soon. Thanks again....