Does the van use diode isolator mentioned.You could ditch diode isolator/combiner and go with a smart battery combine relay ACR. Then there's no need to have a battery sense alternator anymore ,so one you have will work. There are tough to kill but a slight chance isolator went bad and not original the alternator .Look up vid how to test diodes or you isolator with a meter. Would not want to see you buy both and still not get bidirectional charging that you would gain with smart combiner ACR.
A lot of us put Bluesea MTL-ACR in our DPs but you you need to run a few wires to dash to have switch there. Then it will work as boost too, and has a couple flashing diognostic codes. There's a couple stand alone ones as well. Basically looking at about $150 ish
95 Monaco Crown Royale
M11 400hp, 4060 trans.
Aquahot, Generac Guardian7.5k