Originally Posted by
89van
not positive what drivetrain your van has but here's an opinion* on both:
-If your van has a manual transmission: There is a Clutch Safety Switch and a Starter Relay. I would check this relay (Sometimes if relays click, it doesn't mean it's good necessarily!) and the switch for proper operation; an intermittent start sounds like it could be a bad relay imo.
-If your van has an automatic, we have a Neutral Start Switch; this switch allows the starter to engage only in N or P; have you checked if the issue continues if you put it in P then into N, and vice versa?
As for the christmas lights, I believe there is a thread on here that discusses them, search tool will help a lot here. If your alternator is going full-field, that is not good at all! Well undercharging isn't good either too.
*I've had starter troubles in the past; starters for these vans haven't been made in decades and Remanufactured ones are a hit or miss unfortunately. Also consulting my 1989 wiring diagram too from a brisk flip through.