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Hi Guys, I have had my 125 for about a week and I installed oxford overgrips direct to the battery I'm assuming I left them on because I went to leave for work this morning and when turning the key literally nothing happened when reading online I thought they were supposed to turn off if you left them on after the bike is off is anyone able to help me with how I can prevent this from happening and tell me if I'm right?
 

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2008 YZF-R125 (180cc)
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ok - i also have heated grips and they're the best damn thing ever.. However yes wired direct to the battery they have no way of knowing that the ignition is off so if you leave them on they'll run the battery flat, as you have experienced.

However because they use a lot of power you can't really just tap into an existing part of the wiring loom and plug them in there since you'll overload the fuses/wiring - which would mean (ideally) fuses keep blowing) or (less ideally) melting stuff and/or fires.

The possible exception being that if you've switched to LED headlight bulbs they use very little power vs the original bulbs since headlight loom is used to carrying 2x35w halogens. However not all MOT/TUV guys like LED lights and if you have to switch back to halogens to pass the MOT, and accidentally switch the grips on it all might melt or fuses blow. My bike just failed MOT due to LED bulbs this year, though apparently they were fine at the same garage last year hmm :unsure:).

The way I see it you have several options -

1) switch to LED bulbs and then tap into the headlight loom for power since that should be able to handle the additional load from the heated grips. Personally I don't like this option as idk the actual power usage of the grips and you may end up still melting something if it's over 70w. If there is an inline fuse on the grips then that may give a clue as to the actual power consumption (e.g. 5a fuse - 5 x 12v = 60w - would prob be ok.. but if it's 10a fuse - then 10 x 12v = 120w.. NOT ok since headlight loom expects ~70w and even led bulbs use some power). It's still gonna be quite close though so even if all goes well, slight chance of blowing fuses and/or melting stuff.

2) put a big bright LED somewhere you cannot miss it which shows when the grips are on. Quite easy to do and although not foolproof, ought to be quite reliable...still requires a bit of soldering but minimal.

3) do what I did which is put a relay in line with the heated grips and take a (low load/signal) positive wire from the ignition to switch the relay. That way the grips can only be on when the ignition is on but there is no addtional load on the wiring loom from the grips... so the grips are still wired directly into the battery (via the relay), it's just a tiny low-current positive signal wire from the ignition whcih activates the relay to enable the grips - no melting stuff or blowing fuses. I turn the ignition off and the grips go off. It's a bit more complex to install and will require a bit of soldering but so far - number of flat batteries due to grips left on (over 2-3 years riding in all weathers): 0

If you want to do option 3 I can probably help guide you through doing so - but you'll need to be able to solder already, plus it will mean tapping into one of the leads from your ignition whcih is itself quite involved since that plug (big red plug block) sits under the fuel tank just behind the fork stem and is a bit of a pain to get to.

crappy diagram but perhaps illustrates the idea

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