Harbor Freight Tools 40134 - Manual (Page 6)

SKU 40134 Page 6
6. Make the connections to the Compressor (3) and the Electric Relay (5) as
shown on the Wiring Diagram.
Note: Some vehicles may employ a positive ground. If this is the case, refer to
Wiring Diagram Positive Ground. Pay attention to polarity. If the Compressor turns on
and the Horns do not sound, reverse the Compressor connections (+ / -).
Caution: Use caution to prevent accidental short circuiting of power while performing
installation.
Wiring Diagram Negative Ground
Always use vehicle terminal connectors (not supplied) on all connections.
Never wrap wires around terminals as they could fall off. Connect terminal
#30 on the Electric Relay (5) to a 30A fused circuit.