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Discussion Starter #1 (Edited)
I have a 2008 tundra. Yesterday all the warning lights came on. Check engine, vsc, slip control, abs, emergency brake all came on and speedometer stopped working.When I stopped things went back to normal. Started to go again and everything came back on. Went home popped hood and found battery really overheating, hot to touch and could hear it boiling inside. Unhooked battery and removed. Does anyone have any thoughts, electrical short or alternator overcharging battery? Both battery & alternator were replaced 3-4 years ago. Any advice would be greatly appreciated. Thanks
 

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I had a 2008 Tundra. Something similar happened to my truck. All the warning lights lit up. The vehicle wouldn't go faster than 35mph. I limped it into the dealership. They found a bunch of codes on the computer. They cleared them. No problems since.

I used to be a Dealership Harley Tech. I can take a Harley down to nuts and bolts and put it back together. When it comes to the computer, you gotta have the right tool (Scanalizer for Harleys) to see what's up with the computer. Without it, you're lost. Mechanical work on any vehicle I can do. I let the dealer take care of the computer.

3-4 years on an alternator is not long at all. Just long enough to tell you it's working right with no factory discrepancy. The battery may still have a year or 2 left in it. But, I would seriously not suspect the alternator and/or battery as primary problem for what you described. The battery may be toast now, but, unless it never got any maintenance in the 3-4 years you had it, it should not have boiled, unless there was some major power draw on it.
 

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Discussion Starter #5
Thanks to all for the feedback. So this was a new one for me. I checked the battery as soon as i pulled it out and it was right where it should be at 12.6 volts. Looks like the alternator was bad overcharging the battery. The alternator has a bridge rectifier consisting of 3 pair of diodes. These diodes change the AC to DC and when they go bad they can allow AC voltage to bleed back thru causing the issues with the electrical system & warning lights. Apparently the voltage regulator in the alternator was bad allowing the alternator to send 20v back to battery (should be 14-15v) overcharging / overheating the battery.
That's why when I started to go the warning lights came on & when I stopped things went back to normal. More RPMs more voltage.
Got my GED in alternators this week.
Had alternators not charging or undecharging batteries in the past but never thought about them overcharging. Replaced battery & alternator and checked voltages...everything looks good.
Thanks again for the feedback.
 
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