Some vehicles use a ford type starter relay so it disconnects from the remote battery when the towing vehicle is not running, but activates the relay when started so it charges the remote battery.
Partially true. You do NOT want to use a "starter relay." You want to use what is specifically rated and is in fact called a "continuous duty solenoid." An actual Ferd relay won't last long.........perhaps 15 minutes...........before it gets hot and burns up
This is because the coil in a Ford relay is much heavier and draws more current. The reason for this is the current rating on the contacts. "Part of" the engineering behind the current rating on relay / switch contacts is the surface area and the PRESSURE EXERTED on the contacts.
