Relay for heated grips

[lhanscom]

While on the subject of Heated Grips, for those interested in rolling their own, it's an easy job. Pick up some NiChrome wire, I've used 24 awg(McMaster-Carr), which has 1.671 ohms/ft. I shoot for about 7.5 ohms, which yields 20 - 30 watts depending on what your stator is putting out. This works out to ~4.5 feet of wire, just wrap it around the grips, making sure you don't short the wire. You can make a high/low switch if you put 4.5 feet on each grip, and wire the 2 in parallel for high, and series for low. If you just want on/off, you can split the 4.5 feet between the 2 grips, and wire them in series. I've always used electrical tape to cover the wire on the grips, but there is probably a better way. BTW, that 100' spool of 24awg NiChrome is only $10. I did this for years, and they work quite well, I have electric gloves now though, which I highly recommend if you do much cold weather riding.

[jpaul]

Yesterday was my first really good test of my heated grips. It was around 40°, and I got out for about 35 miles of riding. I never went over the 30% setting on the grips, and my hands were comfortable the whole time. I'll give them another test in a few minutes, since the snow isn't coming till after sunset. It's supposed to be in the mid 30's for the afternoon, so it'll be a little better test. I also plan on bringing some other, lighter gloves, just to give the grips a better test.

Thanks Steve, for for the instructions on wiring them up. It was the the same as I had figured, but having a printout and some verification of what I was doing saved me time double and triple checking my work.

Of course, everything couldn't go smoothly for me. I ended up having to replace my fuel lines before my bike was ready to go back on the road. I hate that bastage Murphy and his f%$#ing law.

[Steve]

I hate that bastage Murphy and his f%$#ing law.

Just remember ...

MURPHY WAS AN OPTIMIST.


.

[lurch12_2000]

Steve, since both wires are black to either horn's 2 female spade connectors coming from the wiring harness under the front of the tank, I put the voltmeter on (+ on spade connector and - to frame) and I got a 10.3v reading on any of the 4 wires to the horns with the key on (headlight on) and engine off. The voltmeter reads 11.5 directly at the battery posts with key on(headlight on) and engine off. So there appears to be a little over a 1 volt drop if I wired through the horn circuit. And I suppose it doesn't matter which side I use, correct, as in hot vs ground lead to the horn itself?

So along with what bwringer said, too, there would be a difference of juice to the grips if I wire a homerun vs going through the horn circuit. But I would think the rate (2.8 amps?) of draw would be more important than the a 1 volt difference.

I haven't received my order of grips to hook up yet. If they have to be switch to low anyway, because the high setting may "cook" my hands, then why bother with a switched circuit? I don't plan on any other accessories such as a GPS, etc....
thanks

[Road_Clam]

I am not understanding why the need for a secondary relay either. Generally it's my understanding relays are used when a high amperage switchable device needs to be controlled by a lower amperage 12V feed ? There is no relay system required for my heated vest (although granted there is no chance for a battery drain scenario with my vest, as once unplugged, there is no current draw).
Wouldn't it just be simpler to obtain a key "on" only 12V feed to the heated grips right off the ignition?

[jpaul]

I went with a relay because I wanted to hook the grips directly to the battery. My GS500 doesn't have a fusebox on it. there is only one fuse for the bike. The relay is insurance to keep me from forgetting to turn off the grips. They have a automatic shutoff once the voltage drops below 11.5, which is marginal for starting the bike and keeping it running.