Brushes in electric golf cart motors wear with use. Learn whether your cart has brushes, the warning signs of failure, and safe, step-by-step tips to inspect and replace them.
Do electric golf cart motors have brushes?
It depends on the motor type:
- Brushed DC motors (series/regen): Most legacy and many modern electric carts use brushed DC traction motors. These do have carbon brushes and a copper commutator that require periodic service.
- AC induction / brushless DC (BLDC): Some newer carts use AC or BLDC motors with electronic commutation. These are brushless, so there are no brushes to replace. If your motor label says “AC,” or the service manual calls it brushless, you won’t have brushes.
Check your motor nameplate and owner’s manual. Brushed motors typically have a removable end bell with brush holders visible; brushless motors do not.
How to tell if brushes are bad in a golf cart
The only definitive check is inspection. Look for:
- Short length: Brushes worn to or below the wear line (or < ~50% of original length).
- Chipping/glazing: Cracked edges, shiny glazed faces, or crumbling material.
- Weak springs: Springs that no longer press the brush firmly against the commutator.
- Contamination: Heavy carbon dust buildup, oil/grease on brushes or commutator.
- Commutator damage: Burn marks, deep grooves, lifted bars, or out-of-round surfaces.
Common symptoms of bad brushes in an electric motor
| Symptom | What it suggests |
|---|---|
| Intermittent power or surging (especially over bumps) | Poor brush contact or weak springs causing momentary disconnect |
| Low torque, sluggish starts, struggles on hills | Worn brushes or high resistance at the commutator |
| Excessive sparking/arching inside motor, burnt smell | Brush wear, contamination, or commutator damage |
| Motor runs hot; reduced top speed under load | Electrical losses from poor brush contact |
| Grinding/squeal at low speeds | Brush chatter or rough commutator surface |
| Controller faults under load (voltage sag) | Tired battery pack can mimic this, but bad brushes increase sag too |
How to replace brushes in an electric motor (step-by-step)
Safety first: Work on a cool motor. Park on level ground, chock wheels, wear eye protection and gloves. Carbon dust is messy—avoid inhalation and use non-chlorinated contact cleaner.
- Power down. Turn key OFF. If your cart has a RUN/TOW switch, set to TOW. Disconnect the battery pack (negative first, then positive). Remove the main fuse if equipped.
- Document wiring. Photograph and label motor terminals (A1/A2, F1/F2). Miswiring can damage components.
- Access the motor. Depending on model, you may remove just the motor end bell or drop the motor from the transaxle. Support the motor’s weight before loosening through-bolts.
- Mark orientation. Scribe alignment marks across the end bell and housing to ensure proper reassembly.
- Open the motor. Remove through-bolts and gently lift the end bell. Watch for brush leads and springs.
- Remove old brushes. Lift spring fingers, slide each brush out of its holder, and disconnect its pigtail (spade/ring or soldered, depending on design).
- Inspect and clean. Examine the commutator:
- If lightly worn: polish with a non-conductive aluminum-oxide abrasive (e.g., 600–1000 grit) or a commutator stone. Do not use emery cloth that sheds conductive grit.
- If deeply grooved/burned/out-of-round: the armature should be turned (trued) and the mica undercut by a motor shop.
Blow out carbon dust with compressed air (short bursts, away from bearings) and wipe with contact cleaner.
- Install new brushes. Verify the correct brush grade/shape for your motor. Confirm each brush slides freely in its holder; dress edges lightly if needed. Route pigtails cleanly; avoid pinching.
- Set spring tension. Install new springs if supplied. Springs must press brushes firmly and evenly against the commutator.
- Reassemble. Align your scribe marks and reinstall the end bell. Torque through-bolts evenly (refer to your service manual for specs).
- Reinstall & reconnect. Mount the motor, connect cables per your photos/labels, and secure all hardware. Reconnect the battery pack (positive first, negative last). Return RUN/TOW to RUN.
- Break-in. With the rear wheels off the ground (if safe) or on flat ground, run the motor at light to moderate speed for 10–15 minutes to seat brushes. Avoid full-throttle starts for the first hour of operation.
Pro tips, break-in & when to call a technician
- Brush grade matters: Use the manufacturer-specified carbon grade; the wrong grade can wear quickly or arc.
- Check the charger & pack: Weak batteries mimic brush issues. Load-test the pack and confirm your charger profile.
- Watch temperatures: After replacement, feel the motor housing after a short drive—it should be warm, not scorching.
- Call a pro if: You have an AC/brushless motor, see lifted commutator bars, severe burning, or persistent arcing after cleaning and new brushes.
Bottom line: If your cart uses a brushed DC traction motor, brushes are wear items. Catching the signs early—surging, sparking, sluggish hills—lets you service the motor before commutator damage occurs. With basic safety and the right parts, brush replacement is straightforward and restores smooth, reliable power.