After replacing the battery, the problem still occurs once in a while, but not very frequently - where before the new battery, it was all the time.

 

.....

 

It has nothing to do with the key......if this were the case every electrical option on the van would not work.
I had the same problem plus an additional electrical problem.
There was a wiring harness, part of which took power from the alternator to the battery.
This harness was wet, corroded, and cracked.
I drove one day and eventually my van just died.
Took it to a shop and they traced the dead battery (alternator) problem to this harness.
Since they replaced this harness, I have not had a problem with the wipers/radio/windows/blower etc as described earlier.

 

After spending hundreds to solve the same electrical problem (radio, blower, wipers, window not working when the van is running, and fine when it's not) the problem reoccurred a couple of weeks later. My shop can't find the problem, as it seems OK now. Is the suspect wiring harness the one underneath the battery? Apparently mine suffered corrosion damage at some point, and perhaps should be replaced. Is that a big deal time & money wise?
Thanks!
Jim F.

 

Was there any definite resolution to this problem? I've got a 2002 Caravan that the accessories work fine when the key is only in Accessory position but within a split second of starting the engine, the accessories all shut down.
I was told this was a problem with the ignition switch so I changed it out. The result was the same.
As you can expect, I'm curious to know if the problem is the BCM or some wiring harness. Can anyone advise.
Thanks,

 

I have the same problem and thought i narrowed it down to the BCM also. can you replace it yourself or is it something the dealer has to do? I would like to get one and do it myself. Also my radio, power door locks w/wo key fob, power sliding door, power lift gate do not work, interior lights, and door chime do not work. and the accessory side of the ignition switch does'nt work. The lights work whan the key is on.