Chrysler Repair: 92 electronic cluster: loss of speedo when headlights on

Question
I have an electronic cluster and yes everything else works like wipers, radio, etc... the issue does not happen when the parking lights is on only my headlights. I also don't have daytime running lights.

Answer
Hi Karla,
I don't see an obvious connection between the headlamp circuit and the electronic instrument cluster. The parts of the cluster that fail are those related to information that comes to the cluster digitally on what is called the digital data bus which is a system that connects the cluster/engine/transmission/body computer/etc. together. Because the vehicle seems to run the same whether the lights are on or off would suggest that the digital data bus entirely is not being affected by the headlamps. So it would seem the problem may be internal to the cluster. The power to operate the cluster comes from the ignition switch and that source operates many other items as well. So I would wonder whether the headlamps may be dragging down the voltage on the system such as to impair the function of the cluster.
My suggestion would be to unplug the two headlamp plugs at the back of the lamps to take them out of the picture, then turn the head lamp switch 'on' and drive the vehicle to see if the cluster is then working again. If it is, then we need to focus on the voltage level difference on that main power line to see if the headlamp bulbs (when reconnected) indeed are dragging down the voltage too much. It might be the alternator or the battery were that the case or the could be a short in the headlamp circuitry. But lets try that first and see what happens.
If you have a voltmeter put one lead on fuse 6 or 7 or 8 (all are connected to the ignition switch) the other lead grounded to a shiny metal surface nearby, and see what the voltage reads there with the engine running and headlights "on", and with the headlights off, and with the bulbs disconnected but the headlamps switch turned "on".
Please read the PS below and respond to it.
Thanks,
Roland
I revised the 'subject', above. The ground for the cluster is a black/light green wire on pin 7 that goes to the center lower reinforcement under the instrument panel. Were that loose is might cause this problem too.