Choosing Electrics

I picked up the "older style" BMW heated vest from their trailer at a motorcycle show in St. Louis a few years ago. With its heated collar and decent heat output, it adds substantially to the riding season on both sides of a full-blown winter (I chicken out and park it when there's ice on the roads). My only problem with the vest was when the cord detached at the vest and I dragged it down the freeway far enough that the inline switch literally "disappeared". The dealer wanted a small fortune for a replacement cable, so it was off to Radio Shack. I mounted an illuminated automotive switch in a very small box and soldered it inline with the cable. I expanded the pins on the vest and haven't had any repeat problems with it coming unplugged. Electrics are a great counter to folks that think comfort is just a fad.

Dohp! Part Duh!

BradfordBenn said:

31 Degrees and drizzle.

Mother Nature 1, Electrics 0.

I think it is a day to not ride when you can see from inside that the entire street is glimmering with ice, not just patches.

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Okay so the rain and ice stopped. However not the score is:

Mother Nature 1, Ohm's Law 1, Electrics 0.

I will also post this in the Oilhead Tech Forum cause I figure I am not the first one to hit this little problem...

The Gerbing directions say:

ÔÇ£The accessory plug on BMW bikes is strong enough to power Gerbing's heated clothing. We sell a modified BMW plug that replaces the battery harness for your connection to your bike's electrical system. This modified plug connects to the BMW accessory plug-in on one side and Gerbing's thermostat or on/off switch on the other side.ÔÇØ

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Today the snow and rain stopped enough to go for a ride. I read the directions on the ÔÇ£Portable Temp-ControllerÔÇØ and followed the instruction to have engine running when connecting. Went for a ride around the neighborhood and noticed I was not getting warm. The LED was not blinking on the controller. I went back home and checked the fuse for the accesory socket as the GPS had also lost power. The accesory socket fuse had blown, it is rated for 4Amps. I figured maybe I had done something wrong, and replaced it once again following the directions. Go for a test ride again and still no heat. After doing some troubleshooting, I determined that the root case is OhmÔÇÖs Law.

OhmÔÇÖs Law states that Power (or Watts) divided by Electromagnetic Force (Volts) = Intensity (Amps). I did the math with 77W and 12V and it indicates that the fuse must be rated at approximately 6.5Amps or more than 50% larger. I checked my ownerÔÇÖs manual for my R1150RT and it does indicate that the accesory socket has a 4Amp fuse.

So at the moment I am still cold. However the legs were nice and warm with the HyperTex Overpants.

But the BMW vest is 70W which would also cause the 4Amp fuse to blow... things that make me go hmmm.

My r11rt (2000) came with a 15Amp fuse installed from the factory.

Bernie.