Relay Box

The relay box is a high strength thermoplastic enclosure that contains four relays mounted on a black plastic chassis. The relay box distributes battery power to the Telma in four stages, and is usually mounted on the frame rail between the batteries and the Telma. Battery power is connected to the relay assembly at the "+" terminal. When voltage is applied to terminals 1, 2, 3, and 4, their respective relays close. This switches battery power to terminals I, II, III, and IV respectively. The "M" terminal is used to ground the relay assembly and dissipate the reverse voltage spike that occurs when each stage is deactivated. The "S" terminal turns on battery power whenever any relay is closed. The relay box should always mounted in a vertical position with the wiring coming out of the bottom. The design of the relay box makes it a simple, effective and proven solution. 

When replacing an older relay box JD331121 (12V) or JD332121 (24V), a ground wire will need to be installed between the “E” terminal and ground such as one of the relay box mounting bolts. 

CAUTION! The “E” terminal should never be connected to the “M” terminal.