Hello! I thought I had a water pump leak and when I got home to check it out the Passenger battery was steaming out of the top! After I played a tennis match, and before I drove 15 miles home, I noticed what I thought was coolant from the passenger side. The top of the battery was coated in it and typical right front of the engine compartment. When I got home and under the truck, the water pump appears to be dry and just the battery was causing it. Anybody ever heard of this? THanks!

 

check and clean all the battery post and check cables for corrotion. The ECM reads voltage from drivers side but puts power to passanger side first and over charges it. May need new batteries if still originals.

 

I had the same thing happen in my 2007, cleaned it all up and the terminals and it never happened again. Les Schwab said new batteries the dealer told me no. So I scrubbed them tightened them down and called it good. Went strong until I traded it in a year later. It did ruin my wiper hose connector but that was a quick fix, good luck .

 

I can almost guarantee it's the connections. I've had it happen to me, and I've seen it several times. As kowalski said, what is happening is there is a bad connection somewhere between the pass battery + post and the ECM. The ECM isn't getting a reading (it thinks the batteries are at low volts) so it tells the alt to charge. It charges and charges the pass side battery but due to the bad connection, it thinks it needs to keep charging. This overcharges the passenger side battery and "boils" it. When you clean everything, make sure to take the cross bolts out and clean them too..... that's where the bad connection was on mine: drivers side pos terminal cross bolt. Also, be sure to clean the engine compartment and inner fender to prevent rust. Good luck!

 

UPDATE: Went to the auto parts store and purchased 2 new batteries. Came home and took old ones out, cleaned terminals, etc. Put it all back together and went for a test drive. SO far so good !