DISCOVERY DISCOVERY BRAKE CONTROL INSTALLATION AND USER GUIDE For use with 12 volt negative ground systems only For trailers with two to eight brakes Read, follow and save this guide for future reference 51120-INS-R1 • PAGE 1
This package includes: (1) Brake control module with quick plug (1) Mounting bracket (4) Mounting bracket screws One or more of the following may be needed to complete installation: • Brake control connection harness, supplied with the tow vehicle (if equipped) • CURT quick plug - custom connector for specific vehicles.
Controls and Components 1. Display 2. Sync adjustment 3. Output adjustment thumb wheel 4. Manual control lever 5.
Output Control The output control establishes the maximum amount of power available to the trailer brakes. As the output control is moved to the right, more power will be available to the brakes when the brake pedal is pressed or the manual control is used. The output control should be adjusted during initial setup, when trailer load changes, when different trailers are used or to adjust for a change in road conditions.
Manual Control The manual control lever is located on the front left of the brake control unit. It only applies to the trailer brakes. Manual control is used during initial setup and in situations where a slow reduction in speed is desirable. When the manual control is pushed to the right, the control begins to apply the trailer brakes. The further to the right it is pushed the harder the brakes are applied until the maximum set by the output control is reached.
Mounting the Brake Control NOTE: Avoid mounting the brake control module near a CB radio or other RF transmitter.
1. Determine a suitable mounting location. Mount the unit securely to a solid surface where it is easily accessible to the driver. The area behind the mounting location must be clear to prevent damage while drilling. 2. Hold the mounting bracket in the position selected and mark hole locations through the slots in the bracket. 3. Using a 1/8" diameter bit, drill holes in the marked locations. 4. With a philips screwdriver, secure the bracket in place using the two screws provided.
WIRING DIAGRAM IMPORTANT: Make sure that both positive and ground connections are made directly to the tow vehicle's battery. Connecting to existing wiring or chassis ground, other than the battery terminal, may damage vehicle circuits and could lead to trailer brake failure. Mount a 30 amp, auto reset, circuit breaker as close to the battery as possible.
IMPORTANT: When passing wire through sheet metal, always go through an existing grommet, add a grommet or use silicone sealer to protect the wire from sharp edges. Feed two 10 gauge, or larger, wires, one white and one black, from the mounted brake control to the battery area. Using a ring terminal, connect the black wire to the 'aux' side of the 30 amp circuit breaker. Leave the white wire for connection later.
IMPORTANT: Once a cold side wire is found, test to ensure that the wire is not grounded when the pedal is in the up position. If the wire is grounded, the brake control unit will be destroyed when manual control is used. Reconnect the tow vehicle's negative battery terminal and attach the white, 10 gauge wire previously positioned near the battery to the negative terminal using a ring terminal.
Test Drive In an open area, such as a large parking lot, drive forward and apply the trailer brakes using the manual control. If the trailer brakes are weak adjust the output control to the right. If the trailer brakes jerk or lockup adjust the output control to the left. Repeat this step until firm braking is felt without lockup. Once the output is set, drive forward and press brake pedal. The tow vehicle and trailer should both make smooth stops.
Bench Test Instructions Wire as shown below.
Set the output control to maximum and set the sync control to minimum. NOTE: If at any time during the bench test the display shows OL, make sure that the blue 'brake' wire is not shorted to the 'negative' battery terminal or the white 'battery' wire. If at any time during bench testing, the display shows Er, return the unit to your CURT dealer for further evaluation. Test Standby Condition Hold the red 'stoplight' wire on the '+' battery terminal. The display should show a single decimal point.
Slowly move the sync control to the maximum. The display should change to the sync mode and count up to 9o. Disconnect and reconnect the red wire. The bulb should light brightly with no delay, the display should read 10. Disconnect the red wire. Test Manual Activation With the output control still set at maximum, slowly activate the manual control slide button. The bulb should start dim and get brighter and the display should count up to 10 as the manual control is pushed.
No Trailer Connected Troubleshooting Guide (test without trailer first) Condition Decimal point does not light when brake pedal or manual control is used Display Icon Blank Decimal point does not light when brake pedal is pushed.
