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Discussion Starter #1
Have read all the threads related to the auxiliary power plug located under the upper left hand frame rail/under tank and found it no problem. That plug is switched power and is protected by a 7.5A fuse in fuse box A labeled in the owner's manual as "Optional Key". The wiring diagram at the end of the manual shows a connector item #55 and labeled "heated handgrip power supply" and I assume are one and the same thing.

Few Questions:

1. Does that 7.5A fuse protect just that plug or is there anything else connected to the power supply that I don't know about?

2. If I assume that nothing else is on that circuit except what I connect to it, what determines the 7.5A rating? Is it a combination of the gauge of the conductors supplying that plug and the overall bike load capacity?

3. What could be the potential consequences of replacing that 7.5A fuse with a 10A fuse?

Reason for asking: I wired my heated grips and heated jacket/pants liner to that circuit. Maximum advertised draw of those items is greater than 7.5A and my operational check verified that as I blew the fuse when I asked for maximum heat from both items. I was freezing my ass off at 33 degrees and replaced the fuse on the side of the road with a 10A. Ran at maximum off and on and the fuse didn't blow nor did the battery discharge.

Welcome all replies, from educated to armchair bullshit.

thanks!
 

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Discussion Starter #3
Please post a pick of this aux power plug. I can't find one on my M1200. Could I plug in a phone to it? USB?
I'll dig up a photo later but it's on the left side forward in that small frame triangle area. If you shine a flashlight in there you'll see a white plug that has nothing attached to it. I dug it out with some long needle nose. To actually work on it (splice conductors), I lifted the tank up to make it easier to work. Very little slack.
 

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Discussion Starter #4
Sorry, forgot to answer the rest of your questions. phone, GPS no problem as they don't need much juice. It's protected by a 7.5A fuse so could handle your device(s) power and heated grips no problem. My issue was I wanted it power my heated clothing as well.

It has a unusual plug. forgot the name but if you search on this forum for heated grips, gear etc... you'll find the name. Sumimoto (sp)##. I didn't use the plug, I just used the conductors and spliced to them.
 

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2. If I assume that nothing else is on that circuit except what I connect to it, what determines the 7.5A rating? Is it a combination of the gauge of the conductors supplying that plug and the overall bike load capacity?

3. What could be the potential consequences of replacing that 7.5A fuse with a 10A fuse?
OK, I'm an electrical engineer . . . and my reply is worth just about what you're paying for it . . . :0

The 7.5A rating is determined by the smallest gauge wire used on that circuit, with a bit of conservatism. If you pull 7.5A from that circuit all day long, nothing bad will happen, assuming that everything in the circuit (like connectors) is in good condition. I don't recall the bike's maximum alternator output, but it's not huge, and that isn't directly related to this circuit's fuse choice.

Installing a 10A fuse in this circuit isn't a great idea. Yes, you will get away with it so long as you're not continuously pulling 10A, but I would guess that if you draw 10A for, say, half an hour and touch some of the bike's wiring that's on that circuit, it will be warm to the touch. Will you burn up the bike? Probably not, but you're pushing it. If everything is in perfect condition, you likely will get away with it for a while.

My strong recommendation is to run a properly-sized wire, fused at 10A, directly to the battery. That's what I do, and it doubles as my Battery Tender hookup (I made up a pigtail that plugs directly to my Gerbing's jacket liner and pants controller).
 

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And if you're afraid of leaving it on and draining your battery you can always add a relay.
 
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Discussion Starter #8
OK, I'm an electrical engineer . . . and my reply is worth just about what you're paying for it . . . :0

The 7.5A rating is determined by the smallest gauge wire used on that circuit, with a bit of conservatism. If you pull 7.5A from that circuit all day long, nothing bad will happen, assuming that everything in the circuit (like connectors) is in good condition. I don't recall the bike's maximum alternator output, but it's not huge, and that isn't directly related to this circuit's fuse choice.

Installing a 10A fuse in this circuit isn't a great idea. Yes, you will get away with it so long as you're not continuously pulling 10A, but I would guess that if you draw 10A for, say, half an hour and touch some of the bike's wiring that's on that circuit, it will be warm to the touch. Will you burn up the bike? Probably not, but you're pushing it. If everything is in perfect condition, you likely will get away with it for a while.

My strong recommendation is to run a properly-sized wire, fused at 10A, directly to the battery. That's what I do, and it doubles as my Battery Tender hookup (I made up a pigtail that plugs directly to my Gerbing's jacket liner and pants controller).
Thanks very much for the detailed reply. I took your advice and connected the Warm and Safe clothing power harness directly to the battery. That harness has a 15A fuse. That's what I have done on other bikes but was initially too lazy to do it on this one, because it's a pain to get to and I didn't want the harness showing.

Thanks again.
 

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Yeah, it was a fair amount of work to run the BT wiring, because of the battery location. But I tucked the wires in (and they're black) and zip-tied them along the way, and they come out near the junction of the seat and tank, on the left side, so they're convenient for the Gerbing controller on my suit. You really can't see the wire unless you look hard.

Glad you did it the "right" way.
 
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