Chrysler Repair: Chrysler vision no speedometer / atc when motor is running, fahrenheit celcius, chrysler vision

Question
I have a 94 Chrysler Vision with the following problem:

When i turn the key in starter-position the tachometer and speedometer work properly. Also the fuel and temperature indicator work fine while starting position. When motor is running these controls are dead. also the atc goes back to Fahrenheit (Celcius in europe) and is not working. Only hot air and no control of the blower neither one of the buttons is working on the atc.



When i pull out the last relais onder the hood the speedo is working fine (ac has no display then). Also the windows wont work without that relais (hard to choose: heater on and window open or heater off and windows closed... ).



Also the central lock doesnt work on the door lock, it does function with the switch inside the car.



Hope you can help! (couldn't find excact match).


Answer
Hi Gerard,
I can't quite connect together all the observations, but I would begin with the possibility that you have a faulty ignition switch. When it is in the "run" position check to see whether you have 12V present on behind-the-dash fuses 6,7,21, and 22 or not. {If "not", then the ignition switch section that turns on those fuses is not making contact. You might try spraying some contact cleaner inside the switch to make it conduct again.} Measure between each fuse and any shiny metal chassis part nearby using a voltmeter or a neon glow light. You get to the fuses by removing the left end cap of the dash, which you access by opening the left door.  If that voltage check works out, then please go back through you original question and describe exactly the behavior of each affected device and which relays you are describing. It appears to be an issue of voltage supply which is largely mediated thru the ignition switch.
Roland