In the Shop: Twist Grip Sensor

Twist Grip Sensor

One of the most popular upgrades for Harley Davidson owners is handlebars. Handlebars are typically charged for better comfort, for style, or for a little bit of both. Most aftermarket handlebars are designed to be internally wired. Some handlebar designs are fairly easy to pull wires through, while other designs can be considerably more challenging.

Throttle by wire models give us the challenge of an additional 6 to 8 more wires to contend with. 6 wires are for throttle operation and 2 wires are for optional heated grips. Early twist grip sensors (#32305-08B) had two plugs for these wires. A green plug for the 6 throttle wires and a smaller black plug with the 2 heated grip wires (a black and a white wire). These plugs are aproximately 6 inches from the end of the twist grip sensor and can be extremely difficult to pull through the right side handlebar. Especially if the bar has a 90° bend at the top.

If you are planning a handlebar upgrade and do not want to contend with these plugs, there are two different options that can help make the job a little easier.

Harley Davidson offers a twist grip sensor that has a long, uninterrupted, harness. This TGS is part #32310-08A and costs, at least, $140.

The other option is to cut out the plugs. Before cutting any wires, it is extremely important to take some notes and/or pictures of the wires from the TGS and from the green plug. It is easy to get confused because the TGS has 2 red wires, 2 black wires, and 2 white wires. It is important, however, to notice that the wires are separated by 2 different color shrink wraps. There is one red, one black, and one white wire in a yellow shrink wrap and one of each color in a black shrink wrap. Leave the yellow and black shrink wrap in place to help avoid confusion. Trace each wire to the green plug and you will notice that most of the wire colors change at the opposite end of the green plug. This is where it is important to make a clear reference note. Something like this:

BLACK CONDUIT
Red – Brown
White – Blue
Black – Black

YELLOW CONDUIT
Red – Red
White – Purple
Black – Grey

As always, when making soldiered connections that are to be routed through handlebars it is important to stagger your connections. If heated grips are not going to be installed, simply remove the small black plug and add a small piece of shrink wrap to the wire ends. If heated grips are desired in the future, they can still be added.

Here are a few photos of a twist grip sensor harness that we rewired for a handlebar upgrade on a 2008 FLHR. After eliminating the 2 plugs, we were able to pull all of the wires through the new handlebars with ease.

More videos on Twist Grip Sensor, Fuel Injectors, Intake Seals, Throttle Body