When I start my truck the Volt meter stays at 12 ov under until I rev the engine, then it goes to around 14. Is this normal?

 

Yes it is normal...especially if it's cold. What happens is the grid heaters turn on and suck the juice way down. You may even see that the lights dim and get bright, dim and get bright, etc,etc. This is just the grid heaters turning on and off.

 

Thanks for you help.