1989 dodge caravan volt. regulator

My 1989 van has a new battery 1 month old and the battery is already dead. I have had the alternator test out of the van and it tested ok I also had it tested in the van and the test sayed ok. so my next step is the volt regulator but I can not find it the dealer is no help also. I have been told the volt. reg. is on the driverside fender well but it is not there. I have also been told that it is in the engine module and it cannot be replaced without replaceing the module plus I do not know if it has the right alternator in also any help I would like very much cause I am disabled in wheelchair and my 15 year old son has to help me.
Please email me at [email protected]

Thanks:
Alan