two issues on a recently aquired low mileage 1996 towncar. one is when I start the car I hear ticking from the dashboard and it stops after I drive for a 3 to 10 minutes. two is while driving the A/C while begin to blow out heat. I turn it of and on and the A/C works again, sometimes for a long while sometime for a short while.
I don’t know that car, but off hand I am going to suggest that you may have a vacuum problem, which could explain both problems. The vacuum problem could prevent the blend door from working properly.
Are You A Rocket Scientist, By Chance?
Are you sure you want to tear into this?
Search the web and see if you can find information on your A/Cs DTCs (diagnostic trouble codes), the actual numbers and what they mean.
These systems seem to be quite complicated. I believe your A/C has a self-diagnosing feature. After making sure that the ignition is in the “Run” position, simultaneously press “Off” and “Floor”, release them and within just a couple of seconds, press “Auto”. See if that gives you any fault codes on the display. Pressing “Cool” saves the codes and exits the sel-test. Pressing “Def” clears the codes and exits the self-test.
I’m not sure I know what I’m talking about, but that’s all I’ve got.
CSA
Common Sense is on the right track. You may have a sticking blend door. The codes from the EATC control should help. You can probably find the codes at www.crownvic.net, www.linconsonline.com or www.p71interceptor.com.
The blend-air door is electric, not vacuum. However, this does sound like a problem with the electric blend-air door. Probably the plastic between the motor assembly and the air door has broken.