I bought my Fd used and it has a boost and water temp gauge. How do i tell if the gauges are mechanical or electrical? Also are the defi-d gauges electrical or mechanical?

 

Mechanical gauges will have to be hooked up manually to the source via a hose/temperature probe/pressure hose, etc.
Electrical gauges will just have a couple wires (generally) that hook up to a remote sensor, then the remote sensor hooks up to the same source as the mechanicals.

Frank