Heated Grips Issue – Weird Behavior After Startup

[newowner]

I installed "Koso Apollo Motorcycle Heated Grips" on my bike last year, and they worked perfectly at the time.

This year, I’m running into a strange issue and trying to figure out what’s going on.
Here’s what I’m seeing: With the bike off, battery voltage is around 12-12.4 V, When I start the bike, voltage jumps to about 14.2 V, The battery has been on a tender and seems healthy — the bike starts strong every time with no signs of weakness

Now the odd part:

• With the bike off, the heated grips turn on and heat up normally
• As soon as I start the bike, the grips shut off
• I can’t turn them back on until I reach around 4000 RPM
• Once above 4000 RPM, they work normally again and heat up
• But as soon as accelerate, they shut off aga

The grips are wired directly to the battery and They have a built-in “smart” controller that cuts power if voltage drops below ~11.5 V
I’m a bit puzzled with this.. could it be the wiring routing ? thoughts ?

 

[Andrew Shadow]

Not being able to turn them back makes me suspicious of the built-in controller. Assuming that it is not an issue with the controller built in to the grips, after making sure that all connections are correct, clean, and tight, I would start by trying to get some data by attaching a voltmeter and checking to see what the voltage is at the various points where things change. i.e. What is the voltage after you start the engine and the grips won't come on. What is the alternator voltage output below 4,000 RPM when they won't come on vs above 4,000 RPM when they will. What is the voltage at the moment when they cut out when you are accelerating.

 

[SMSW]

I assume you mean by "But as soon as accelerate, they shut off aga" when the rpms increase. If this is correct, then you can test the voltages with the bike on the center stand. Clip your multimeter to the battery, start the bike and see if you can replicate the problem. Either the voltage sensor in the controller is faulty or you have some strange voltage fluctuations in the bike's system (unlikely).

If the controller shuts off the grips when the voltage drops to 11.5 turning the bike off with a healthy battery would not necessarily close them down. Does not sound like the controller is very smart.

 

[Al st1100]

Need to check batt voltage at controller, could be a bad connection. Grips should shut off at startup, voltage will drop below 12v, normal. Also check and monitor battery voltage from startup to idling. Battery could be weak and not recovering to normal voltage. Even at idle it should be charging over 12.5v enough to operate grips.