General vehicle thread

[SideShow Bob]

Went and got the tundra battery tested and it was bad. Rated at 875cc and tested at 486cc. Hopefully that was the cause.

A little late to the party, but check voltage at the battery terminals while it is running. If you have jump started both of these vehicles in the past, especially the GMC you may have fried the rectifier/regulators built into the alternators.
This is a more frequent problem as the manufacturers are using cheaper and cheaper components to build cars nowadays.
After starting and give a minute or two to stabilize, you shouldn?t measure no more than 14.6 -14.8 VDC. Also get a fairly inexpensive digital voltage monitor that plugs into your cigarette lighter and monitor the voltage while driving. The same voltage range should apply.
If you are reading 15.0 VDC or greater while driving, you are over charging your battery and damaging it & shortening the the battery life.
Don?t go by the analog volt meter in the dash, it is very inaccurate.

You can buy the internal rectifier/regulator fairly cheaply and it is a easy job to replace them unless the alternator is in a hard to reach location.