LANCE 1985 - Electric Brake Controller Replacement

LANCE 1985 – Electric Brake Controller Replacement

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Complete repair guide for the LANCE 1985 – Electric Brake Controller Replacement.

Parts & Tools You’ll Need

Step 1: Diagnose Existing Brake System and Gather Tools

Start by disconnecting the negative battery terminal on your tow vehicle to prevent electrical shorts during installation. Locate your Lance 1985’s existing brake controller (if present) and test it with your Circuit Tester / Multimeter to confirm it’s non-functional—you should read no voltage output when the brake pedal is depressed. Gather all required parts including the Tekonsha P3 Proportional Brake Controller, Dexter Axle Brake Wiring Kit, Plug-In OEM Adapter Harness, 7-Way Blade Trailer Connector, Brake Controller Mounting Bracket, Wire Loom Split Conduit, and Crimp Butt Connector Assortment. Take photos of your current wiring configuration before disconnecting anything, as this will serve as a reference during reassembly.

Step 2: Remove Old Controller and Prepare Mounting Location

Disconnect all wiring harnesses from the existing brake controller by gently pulling the connectors apart—avoid yanking on the wires themselves. Unbolt the old mounting bracket from the driver-side dash or firewall area using a socket set, noting that fasteners are typically 10mm or 12mm bolts torqued to 8-12 ft-lbs. Clean the mounting surface thoroughly with a dry cloth to remove dust and debris, ensuring good contact for the new Brake Controller Mounting Bracket. Inspect the mounting location for any corrosion or damage; if present, sand lightly with fine-grit sandpaper and wipe clean before proceeding.

Step 3: Install Mounting Bracket and Position Controller

Position the new Brake Controller Mounting Bracket in the same location as the original, ensuring it sits flush against the mounting surface. Drill or use existing holes to secure the bracket with the provided fasteners, torquing bolts to 10 ft-lbs to prevent over-tightening and bracket cracking. Slide the Tekonsha P3 Proportional Brake Controller onto the mounting bracket until it clicks into place, confirming it’s seated fully. Verify the controller face is easily readable and accessible from the driver’s seat, and that no wires will be pinched by the bracket or adjacent components.

Step 4: Run and Secure Brake Signal Wiring Through Conduit

Identify the brake light signal wire from your tow vehicle (typically a brown or red wire at the 7-Way Blade Trailer Connector) and trace it back to the brake light switch. Run a new wire from the brake light switch to the Tekonsha P3’s brake input terminal, protecting it with Wire Loom Split Conduit (1/2″) along the firewall and under the dash to prevent abrasion. Use Crimp Butt Connectors rated for your wire gauge (typically 18-gauge for signal wires) to create secure connections, crimping firmly and tugging to verify the connector won’t slip. Secure the conduit at 12-inch intervals using zip ties or adhesive-backed clips, keeping it away from heat sources like the engine manifold.

Step 5: Connect Power and Ground Circuits to Controller

Run a dedicated 12-gauge power wire from the positive battery terminal through a 30-amp fused relay to the Tekonsha P3’s power input, using an in-line fuse holder positioned within 18 inches of the battery. Strip 1/4 inch of insulation from all wire ends and crimp secure connectors rated for 12-gauge wire, then insert into the controller’s power terminals according to the diagram on the device. Connect the controller’s ground wire (typically black) directly to a clean, unpainted metal surface on the vehicle frame using a M6 bolt torqued to 8 ft-lbs; do not use plastic grommets or painted surfaces. Double-check all connections with your Circuit Tester / Multimeter to confirm continuity before proceeding.

Step 6: Wire Brake Actuator Circuit to Trailer Connector

Route the Dexter Axle Brake Wiring Kit’s actuator wire from the controller to the 7-Way Blade Trailer Connector, again protecting with Wire Loom Split Conduit and securing at regular intervals. Connect the actuator wire to the white or yellow terminal on the 7-Way Blade Trailer Connector (confirm polarity on your specific trailer’s schematic) using a Crimp Butt Connector appropriate for the wire gauge. Ensure the Plug-In OEM Adapter Harness is firmly seated into the 7-Way Blade Trailer Connector, pulling firmly on the connector body (not the wires) to confirm no play. Test the connection visually and with a multimeter to verify no loose strands or reversed polarity.

Step 7: Perform Full System Test and Verify Brake Response

Reconnect the negative battery terminal and start the tow vehicle engine, then wait 30 seconds for all systems to initialize. Press the brake pedal firmly while observing the Tekonsha P3 controller display—you should see the brake intensity indicator needle move from 0 to approximately 7-8 on the scale, confirming the proportional signal is being received. Reconnect your Lance 1985 trailer and have a second person observe the trailer’s brake lights while you press the brake pedal; lights should illuminate immediately and brighten with increased pedal pressure. Use your Circuit Tester / Multimeter to confirm voltage output at the 7-Way connector (typically 5-12V depending on brake application), and verify that releasing the brake pedal causes the indicator to return to zero within 1 second. Test the manual brake adjust dial on the controller by rotating it fully left and right, confirming smooth operation without grinding or clicking sounds.