Chrysler Repair: 1988 chrysler new yorker-a/c, wheel dirve, chrysler new yorker

Question
The a/c heater display has no power, the a/c runs continously until unpluged at compressor. The blower runs full speed until fuse is removed. All fusescheck good ,is there another source of power to the a/c heater controls ?

Answer
Hi John,
Sorry to be slow in getting back to you. The option you chose to respond is one that doesn't alert me to look for it. Use the 'rate the expert' tab in the future.
The #11 fuse also powers the back-up lamps, the cornering lamps, and the rear window defogger relay. So you would probably want to pull the bulbs on the lamps to see if that cuts the short to ground on downstream side of fuse 11, and pull the plug on the ATC to observe similarly, and then the rear window defogger switch. One of those systems is shorted to ground.
Roland




Hi John,
There are two fuses for the system, #10 and #11 under the dash. So look at those carefully, even check both sides of the fuse socket to verify that they are patent. #11 feeds the ATC module on its blue color 21-pin plug at pin #2 on a white wire. So verify that pin 2 is getting 12V when the ignition is on. #10 feeds the blower. The ground for the ATC module is pin #1 and that is tied to a common ground on the left side dash reinforcement for many other circuits. If you have the power and the ground, and no controls nor display I would have a look inside the module to see if you can find any electrolytic capacitors that have opened and show signs of leakage of the electrolyte on the circuit board. They are pushing 19 years so are ripe to fail.
These pins, etc. are from the '89 New Yorker front wheel dirve wiring diagrams. Let me know if you believe that they might not apply to your vehicle.
Roland