Chrysler Repair: 1999 Chrysler Concorde ATC unit:: illumination flaky, 1999 chrysler concorde, variable illumination

Question
QUESTION: readout does not always light up on ATC unit. Most of the time, it doesn't. Any idea
Thanks


ANSWER: Hi Mike,
The variable illumination level is fed on the orange wire at pin 4 of the plug to the atc. That feed goes to many other illuminated modules so if it is only the ATC illumination that is flaky it would be a problem at the circuit board between the plug and pin at the board (reheat the solder joint at the board). Pin 1 and 3 are ground leads so check those as well. Those attach at the lower center (slightly to the left) of the instrument panel at the firewall (it appears) so be sure you have good continuity to ground on both those pins of the plug. The orange wire comes from a multi-wire splice behind the cluster (upper left corner) so that might be a last place to look for a flaky connection of none if the other bear fruit.
Roland

---------- FOLLOW-UP ----------

QUESTION: Hi Is plug your referring to a plug that plugs into back of ATC unit ? LED readout usually doesn't light up, temp # etc. Where is circuit board between plug & pin ? Do I need to remove ATC unit ? If so, does center plastic just pry out ? anything special  thanks again

Answer
Hi Mike,
The ATC controller is thin, being electronic, so that when you simply gently pry the center plastic panel you are in effect removing the ATC control. The plug in question is the one with 12 pins and is on the rear side of the plastic bezel in the area of the ATC control panel. I haven't seen the inside of the unit, but my assumption is that there is a set of 12 pins on the back side of the plug socket that attach it to the circuit board. Those pins would be soldered to the circuit board. I see there is a second plug as well, but it has fewer wires. That one is for the cabin temp sensor. And a third plug to the side is for the VTSS light and sun sensor.
Roland