Chrysler Repair: 86 New Yorker ATC blower motor control, soldering pencil, electrolytic capacitor

Question
The car has an all electronic ATC head unit. Only the High blower speed works but the lower blower speed setting do not. I would like to know if that is on a separate resistor and where that resistor is?

Answer
Hi red,
The blower speed is controlled by an electronic "power module" that is built-in to the under-dash housing proper. It is not a 'resistor block' as is used on the convention 4 speed blowers.
If you remove parts of the dash you can see the front of the unit where just to the right of the center tunnel is a irregularly-shaped structure called the power/vacuum module. On the left side of that module there is a square opening into which several plugs are pushed. That is the power module which you will need to service. It may be that an electrolytic capacitor is blown, or one of the transistors so if you have any electronic experience and a soldering pencil you may be able to repair the circuit to re-establish the multi-speed function of the blower. The alternative is to try to find one in a junk yard. This type of unit was in production thru the  1990 model year. You will need to remove the glove box and valence assembly, the lower center console, the lower floor air distribution duct, and the panel air distributrion duct to gain good access; then remove the four module attaching screws, disengage all the plugs and vacuum lines, pull the pvm out of the housing and out from under the instrument panel. Then you will have it where you can troubleshoot the circuit board.
Let me know if I can be of further help.
Roland