Variable switch for heated grips

[Big T]

My bike came with heated grips and a 3 position toggle switch (low/off/high)

Low does almost nothing and high is too hot. How can I get a small enough variable switch that will work?

[kdo58]

http://www.ebay.com/itm/Manual-Dimmer-Switch-for-LED-Strip-Light-12V-8A-Mountable-with-Terminals-/251985183083?hash=item3aab7cc16b

this is what they recommend on ADV

[Steve]

I would like to see the specs on that "dimmer".

If it is simply a tapped variable resistor, it's going to draw a LOT of current (same as HIGH setting) any time the heaters are ON.
Some of the power will be diverted to the heaters, the rest will be sent to ground.

A better alternative would be an active system that uses pulse-width modulation.

The difference in the way the two controllers work is similar to our situation with shunt- or series-style regulators.

.

[posplayr]

The unit Kudo58 linked is a very nice unit.

DC to DC convertor. I have 3. 1 of 3 would not go real low so the seller shipped me another for free.

http://i449.photobucket.com/albums/qq215/posplayr/heater_control_zpsa0clkxzw.jpg

[Grimly]

Simplest of them all is a series / parallel switch. Series the bar heaters = high resistance = low heat. Parallel them = low resistance = high heat.
It just works, and has been working on my inner bar heaters for 25 years.
Of course, it depends on how the more conventional over-grip heaters are constructed. If they're not all that robust they might not like being high for very long.