Rad Power Bikes Radster, RadWagon 5 and RadExpand 5 Plus: error 24 on the color display

Your Radster Road, Radster Trail, RadWagon 5 or RadExpand 5 Plus powers on, but the color display shows error 24 and the motor won't help, or it jerks and stutters. These four models use Rad's Color Display, and on it error 24 is a motor hall fault, a connection problem between motor and controller. The short answer: start with the motor cable connector on the chain stay. If it is clean and the code stays, the fault is most likely in the motor cable, the hall sensors inside the motor, or the controller, and that is a job for Rad support or a shop.

Most likely cause

Hall sensors in the hub motor tell the controller where the magnets are, so it knows which coil to power next. Error 24 points to the connection between the motor and controller (Color Display error code table). The first fix is to unplug the motor cable at the chain stay, check it for damage or moisture, reconnect it and power on. The code often means a motor hall fault (error 24 troubleshooting guide).

When a hall signal drops out, the controller loses track of the motor. The classic signs are jerky starts, stutter or vibration at low speed, a motor that only runs once the wheel is already rolling, growling, behavior that changes when the motor cable moves, or no motor at all while the display and battery seem normal (hall sensor testing guide). These signs don't prove the sensor itself is bad, because cable, connector and controller faults look the same.

Other causes to rule out

• A wet, dirty or damaged motor connector. Check this first. (Rad code table)
• A crushed, sharply bent or rubbed through motor cable near the axle or dropout, which can break one hall wire. (EM3EV)
• A connector with corrosion, pushed back pins or loose terminals. (EM3EV)
• A controller fault that cuts the hall supply. (EM3EV)
• If the screen shows 23 rather than 24, that is a motor phase fault, often from heat on climbs. See error 21 or 23 after climbing.

How to confirm

1. Photograph the code. Power off, remove the battery, and press and hold the power button to drain leftover power.
2. Find the motor cable where it runs along the chain stay. On the Radster and the RadWagon 5, this connector screws together, so unscrew its collar before you pull it apart. (Radster guide, RadWagon 5 guide)
3. Pull the halves straight apart without twisting. Look inside both for water, dirt, corrosion, or bent or pushed back pins. Photograph anything odd.
4. Reconnect with the notch, pins and arrows lined up, press straight together and tighten the collar.
5. Reinstall the battery, power on, and see if the code clears.
6. With the bike on a stand, follow the cable from the axle to the connector and look for crushed, kinked or rubbed spots.
7. If the code comes back, note whether moving the cable changes anything, then stop and contact Rad Product Support with your photos.

Fix options

Reseat or clean the motor connector (easy)

This is often all it takes when the connector has worked loose or picked up grit. You only need replacement zip ties if you cut any.

Replace the motor cable or hall sensors (pro, needs soldering and electrical experience)

The hall wires run through the motor cable into the motor. Repairing a damaged cable, or replacing a failed hall sensor, means opening the motor, taking the stator out of the hub, desoldering the bad sensor and fitting a new one (hub motor hall sensor replacement guide). Go inside the motor only after outside tests point there, and only with qualified help. If your bike is under warranty, ask Rad before anyone opens the motor.

Replace the motor wheel (moderate, with support guidance)

Fitting a complete replacement motor wheel avoids opening the motor. It means removing the rear wheel, moving over the brake rotor, drivetrain parts and tire if the new wheel comes bare, and plugging in the new motor. Rad's RadRover rear wheel replacement video shows the general job on another model. Get the correct motor for your exact model and year through Rad Product Support.

Replace the controller (pro)

If a known good motor still throws error 24, the controller is next. Leave it to Rad or a shop.

Parts

• Zip ties
• Motor cable or complete motor wheel for your exact model, through Rad support
• Controller, only if a pro confirms it

When to get a pro

Get help if the connector shows water or burn marks, the cable is damaged, the code returns after a clean reseat, or anything points inside the motor or controller. See when to call a pro and the Rad Power Bikes error codes page.

Sources

• Color Display error code table, support.radpowerbikes.com
• error 24 troubleshooting guide, support.radpowerbikes.com
• Radster guide, support.radpowerbikes.com
• RadWagon 5 guide, support.radpowerbikes.com
• hall sensor testing guide, em3ev.com
• hub motor hall sensor replacement guide, EBIKES.CA
• RadRover rear wheel replacement video, youtube.com

Stuck after these checks? Find a shop near you.