[Jack Innes]

Originally Posted by Lynn Eades

Do you mean the single terminal one is a switch? I understand they are wired in series- single teminal to the second sender, and the other terminal of that one goes to the guage.
If that is the case, then are there two types of single terminal ones? a switch type, and a sender type? (a sender type for motors with only one sender)

Lynn, You are correct, there are single terminal senders that are either a switch or a rheostat type. The switch type is also used on vehicles with an "idiot light" on the dash. The two senders are actually wired in parallel. Either one will take the power to ground when activated. The rheostat does it progressively while the second sender is either on or off. The two terminal type have one terminal with two mounting points to create a connection to the second sender. The 2 sender system actually carried over on some later Y-block engines. I have it in a US built 54 Ford.