Got nice, solid 85 4Runner Sunday. On 6 hour drive home power windows got weak. Stopped for gas halfway , wouldn't start. Threw new battery in it, made it home ok. Next morning died after 10 miles. Had alternator checked. Obviously something draining two batteries, but alternator good as it checked out ok. Have cleaned all connections and will do the same to ground when I can Saturday.
Any other ideas for possible problems to look for?
Thanx, Matt

 

This may sound strange, but an alternator can test good but still be bad. I had this same thing happen on my 86 4Runner, the alternator on my 4Runner showed that it was charging but the battery kept going dead, so i replaced the alternator with an upgraded 100 amp alternator and i have not had any more problems.

 

LONG HOT week.....got new alternator in today. Cleaned all connections, ground also. Gonna just drive short close trips this week, as it took nearly 2 hours to run down battery before. hope this works. Love this thing!! Spent the day stealing and swapping parts from my '87 for it while brother worked on '87 timing chain.