GGAutobiz: 2000 Toyota Sienna CE : Intermittent No Crank

Got this Sienna in the shop that sometimes has to be boosted with jumper cables to start, according to the customer. It has been looked at by other shops but no cause found. I noticed the battery is a Toyota brand dated 11/17 so not very old. The car had just been jump started to drive here and I pulled it inside still running. After parking and shutting off I put the charger on and saw a 69% charge. I let the charger stay on until reaching 100% late last night. This morning I did a quick reconnect and saw the battery back to 90% so I'm already suspecting there is a drain.

That hunch turned out to be wrong.

Back to plan A then. I should have enough charge to do the battery testing. I'll start the engine a few times with lights and accessories on to dissipate any surface charge and get a more accurate test. Also, I like to disconnect the battery terminals and test directly from the posts with no possibility of the car wiring affecting the result. Since I'll be disconnecting the battery I like to put a memory saver in place to help the car retain system memory.

Well the current draw is in within specs and the battery tests good (but is still a bit less than a full charge). I'll check the alternator output, put the charger back on to get 100% again and monitor this thing for a day or so. Meantime I can check for related bulletins. Hold on. Found a problem. I put the old battery load tester/meter on for a quick check. Battery still tests good with load test but the alternator is barely registering. With no accessory load it is not a good charge and with accessory load it sometimes drops to no charge at all. Retesting with a more accurate tester and yes the alternator is indeed bad. Belt is still original as well.