Chrysler Repair: electrical problem 01 T&C:relays clicking while engine running, voltage gauge, battery clamps

Question
Radio and heater fan goes on and off when van is running. All the relays in the
fuse box click on and off and there is a clicking in the right rear panel in cargo
area. This all stops if the engine is stopped but with the key in the run postion.  

Answer
Hi Al,
That is a very strange behavior. The clicking of the relays and the alternating on-off of the blower and radio (which are also relay-related devices) makes me wonder if when the engine is running there is something going wrong with the charging cicuit such that the voltage from the generating system is being intermittantly shorted out. If the voltage drops on the circuits that power the relay actuating coils, then the relay may very well open, which cuts the power to whatever the relay powers. When the engine isn't running it simply runs off the battery voltage which should be stable.
Do you notice an oscillation of the needle on the voltmeter in the instrument cluster (if you have such a meter), perhaps in synchrony with the clicking? How is the battery charge holding up?
If you don't have a voltage gauge, then I would want to put a voltmeter on one of the battery supplied lines, basically any of the fuses under the dash would serve, and observe for whether there is voltage instability. Also, I would check the battery clamps, and trace the - post clamp's wires to all the places where they ground to be sure you have clean and tight ground connections.
It must be something quite fundamental in the electrical system like a loose battery clamp or ground connection, or a failing alternator to cause this sort of clicking which seems to be related to an inability of the relay actuation coils to sustain the closed condition of the relay contacts.
I hope this gives you some ideas to work on. The stopping of the problem when the van is not in motion adds to my suspicion that you may have a loose battery connection or loose ground wire.
I would be interested to learn what you find out. If you don't get anywhere with it, I suspect a good auto electric technician will be able to figure it out quickly.
Roland