do all CUCV's drain their batteries?

[GM 1008]

Only one battery gets drained, the one the alternator in question. Thank you so much for your prompt reply. Have a pleasant day Stinewalljac

 

[GM 1008]

Thank you Doghead, your help was greatly appreciated.
Have a pleasant day.

 

[Thrill 6]

I left my truck in a parking lot for 2 weeks (1984 CUCV M1009). The Gen 1 light started flickering when it started and that was 5 days ago. Didnt think about it too much because she was starting up. Been driving her pretty steady since then, light still flickered and no she aint starting. New alternators and new batteries, as in within the last 3 months for those items. I did have the BO light switch in the on position when I left. I have not had it load tested yet.... any recommendations or thoughts?

 

[vanaisa]

Parasitic drain.

 

[CenterMass762]

I left my truck in a parking lot for 2 weeks (1984 CUCV M1009). The Gen 1 light started flickering when it started and that was 5 days ago. Didnt think about it too much because she was starting up. Been driving her pretty steady since then, light still flickered and no she aint starting. New alternators and new batteries, as in within the last 3 months for those items. I did have the BO light switch in the on position when I left. I have not had it load tested yet.... any recommendations or thoughts?

If everything is operating properly, leaving the service light switch on isn't going to cause it to go dead in two weeks. My batteries are pretty weak and my Gen 2 has bad diodes and I can leave my truck parked for months with the service light switch on and not have an issue. In fact, I never switch it off. You have some sort of drain going on.