1999-2001 Yamaha Phazer 500 / Venture 500 service manual, Page 177Get this manual
GRIPWARMERSYSTEM 8E301
IELEcl 01
GRIP AND THUMB WARMER COIL
1 Disconnect: Grip warmer leads CD Thumb warmer coupler 2Connect:
Pocket tester (to the grip warmer coil leads andor thumb warmer coil coupler)
3Check: Grip warmer CD continuity Thumb warmer continuity No continuity Replace both grips together or separately andor the handlebar switch