7-Switch Box: Wired Simplified | Quick-Fix Diagnostics

STEP 1: Wire the Heavy Compressor Power & Switch Box Feed

• Connect your heavy 8-gauge main power wire directly from the positive battery terminal to Terminal 30 on the 4-pin relay.

• Connect the Red Power Wire from your handheld switch box harness directly to that exact same Terminal 30 on the relay. (This utilizes your main 8-gauge battery line to cleanly power the controller right inside the trunk, eliminating the need to run a separate power wire back up to the dashboard).

• Connect the air compressor’s positive power wire directly to Terminal 87 on the relay.

• Ground Terminal 85 on the relay to clean, unpainted chassis metal.

STEP 2: Route the Single Ignition Trigger Wire

• Route a single, low-profile 18-gauge primary wire from a 12V keyed ignition source at your factory fuse box (such as the radio or wiper circuit), under the carpet, and back into the trunk.

• Connect this single ignition wire directly to one of the two terminal legs on your tank-mounted air pressure switch.

STEP 3: Complete the Relay Trigger Loop

• Connect a short jumper wire from the remaining open leg of your tank-mounted air pressure switch directly to Terminal 86 on your 4-pin compressor relay.

The Operator Note for the Builder:

PRO TIP: Because this advanced layout powers your controller directly from the main trunk line, the switch box will have constant standby power. Always turn your handheld controller’s Keyed Lockout Switch to the OFF position when parking or storing the vehicle. This completely isolates the circuit, prevents unauthorized tampering at car shows, and protects your battery from parasitic drain.