Originally Posted by choppastyle
Right one is super hot like it should be. Left hand grip isn't working at all. Any suggestions?
Troubleshooting this stuff can be frustrating sometimes - so you need to structure your steps and have a logical plan of attack:
1) Since one is working, we start with the assumption that the handlebar switch is OK and that the fuse is OK (only 1 fuse for both).
2) Each side (Left and right) has a simple 2 wires connectors that leads into a 4 wires WHITE PLASTIC connector behind the fork (see attached picture).
Unless you have very small hands, you will need to remove the front fairing and 1 or both side fairing to test the Voltage and Resistance at the connector.
3) With the ignition OFF, using an OhmMeter, compare the resistance of each wire pairs (Left and Right) - you should unplug each pair from the big White connector so that you are reading the resistance leading to the heating element only. BMW has not documented the value in OHMS, but for a working Heated-grip the resistance is fairly low. When the element is shorting or one of the wire broken between connector and Grips, teh resistance is very high or infinite. Compare the good working side resistance with the other side - they should be close when all is OK.
4) If you could not conclude a defective grip in the test above, you should now test for voltage at the WHITE connector for each side (each pair of wires). With Ignition ON and the Heated-grip switch at HIGH, you should read close to 12 volts for each side. If I remember (not 100% sure), when the heated-grip is set to LOW, you will get a lower voltage (approx 6 volts). Watch your time as you work with the Heated-grips ON as you may drain your battery - 5 min should be OK.
If you have found a problem in step 3 (most common cause) you might be able to repair by removing the rubber only and checking if one of the wires is cut inside the grip-tube. You can buy 1 side only from your BMW dealer, but it is not cheap (approx $110 each) - you get the "heated-tube + rubber + wires" as an assembly.