Back It Up! Harley Reverse Issues
We have had a lot of questions come into Fix My Hog concerning Tri Glide reverse issues. We wanted to share what we have learned about this system. Hopefully it will help our members have a better understanding of the assembly and be able to diagnose issues that may arise with their Trikes, or a friend’s Trike.
The reverse motor is powered by the motorcycle’s battery when the motorcycle is running and the transmission is in neutral. It is designed only for a light load and short durations of use. Trying to climb steep inclines or attempting to travel long distances in reverse will drain the battery and can cause the reverse circuit breaker to trip.
Excessive resistance in reverse is the most common reason for problems to arise and reverse components to fail. The reverse system consists of six basic components. A reverse motor, reverse motor solenoid, reverse control solenoid, a reverse control module, a 150 amp manual reset circuit breaker, and a reverse hand switch. The reverse motor and reverse motor solenoid look, very much, like a starter motor.
In order for the ECM to enable the reverse function, there are a few things that must occur: The reverse switch must be pressed. Transmission must be in neutral. The bike must be moving less than 2 mph. The engine must be running at, less than, 1500 RPM and there must not be any reverse codes that are present.
When reverse is enabled, the ECM activates the reverse telltale lamp in the speedometer and “informs” the body control module of the reverse status via a CAN (BUS) message. The BCM then supplies battery voltage to the reverse control module (RCM). Next, the RCM sends a signal to the ECM and the ECM sends a 5 volt signal to the RCM. Finally, the RCM activates the the reverse motor solenoid which causes the reverse motor to engage and the vehicle to move in reverse.
Image of circuit breaker
This is a basic overview that you must understand before attempting to diagnose reverse system failure. In our next “In The Shop” we will get into diagnostic tips for the Tri Glide reverse system.