5000CS overcharge

[Steve Crosbie]

My 87 5000CS is overcharging.  I am measuring 17.3 volts off the battery
measured by a  voltmeter and the climate control diagnostic channel 11
while the car is running.  Originally the car was not charging enough,
we installed a new regulator which did not fix the problem.  Next we
swapped alternators with a good one in another 5000CS and put the new
regulator in it.  It worked for a week and now we have this overcharge
condition.  The battery volt light comes on erratically.

Other possibly related problems:
1.    When the headlights are turned on, the dash lights and climate
control lights turn off, unless the headlight switch is moved extremely
slow. (replaced turn signal/headlight switch with a working one and
problem persists)
2.      The fans kept going when the off button on the climate control
button was being pushed.  This only happened twice immediately after
starting the car.
3.    Sometimes times when I accelerate the climate control lights get
brighter.  These last three problems have started within the last month.

Note: the rear cigarette lighter was found to be pushed in a few days
ago, but is now out and all problems are the same.

Thanks in advance for any help

Steve