chevy astro van 96, put in 4 alternators, then new battery, then used instrument cluster, yes it works, 4 weeks later, no juice to battery.Also the oil guage on cluster went haywire but my son said it has nothing to do with it. van has 271,000 miles on it thanks to son
Why did you do all this in the first place? And were any of these alternators bench tested?
If your son believes that the oil gage cluster, which is an electrical instrument that has the potential to (a) cause the gage to go wild and (b) cause a parasitic battery drain isn’t the problem, what does your son think IS the problem?
You’re wildly guessing and throwing parts at whatever the problem is. Kudos for trying, but this’ll need a real shop to solve, perhaps even one that specializes in automotive electrical systems (hint hint). You have a wiring problem, likely a short to ground.
Assuming all of the wire connections to the starter and battery and alternator are clean and tight, you might want to see if you have dead short. But “no juice to battery” suggests a connection, since you have replaced the battery an alternator and even the suspected source of a short-circuit.
What happens when you jump the battery? Does it even try to start? Is there no change?