The picture on the left is an example water temperature gauge with all the parts that make it operate. Notice a bulb-shaped sensor attached to the end of the tube. This sensor goes inside the engine block or head and makes contact with the engine coolant. This is a mechanical gauge. No electricity required.
The picture on the right is a typical 6 volt bulb that shines light into the gauge cluster.
Which bulb are you talking about? I need to get this straight (understood) before we can continue.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
