I recently purchased a 99 Grand Caravan- and when I brought it home
none of the cimate controls would work at all.  Very quickly I realized
that the battery in the van was so bad that when I got home it wouldn't
start and it refused to take a charge.  After replacing the battery-
the fan switch worked, but none of the lights for the a/c, defrost, and
rear wipers would light up or respond.  Now its a situation where
occasionally when I first turn on the key- they light up and function,
but after hearing a relay in the fuse box under the dash either click
once, or start to click repeatedy- the lights go back off.  I tried to
get it to go into test mode- and it starts- but after a few seconds
(and that relay clicking the whole time) - all the lights go off again.
I tried swapping the relay with another identical one- with the same
result.  Does this sound like the climate controls need to be replaced,
a relay issue, or something worse.  Thanks SO much for any help you
can give me- this is driving me nuts (and killing me without being able
to turn on my A/C in this lovely 90 degree heat).