Voltmeter Power Connection on Special Model

5twins

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On the multi-fuse Special models, there really is no good readily available connection point inside the headlight for the power lead of a voltmeter. Any spot you choose has already gone through multiple splits or connections and at least two fuses. This usually results in a meter reading several tenths of a volt lower than at the battery. There is a good connection point, the brown wire coming out of the ignition switch. This is the only spot you'll find switched power that only goes through one (the main) fuse. But, there is no way to connect here unless you add it, so here's how I do it ....

First, the candidate for this, the original ignition switch off my buddy's 1980 SPII. Also pictured is the little pigtail I'll be adding, clipped from an old wiring harness .....

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As you can see, the "new" wire is pretty grungy and will require a good cleaning .....

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For this, I use a product called the Tannery. This is wonderful stuff that's been around for many, many years. It's excellent for cleaning plastics, rubber, vinyl, and leather. After spraying and wiping down the wire itself .....

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..... I spray a little in a plastic cup and scrub the wire and bullet connector cover really clean using Q-tips. As you can see by how dirty the Q-tip got, it does a great job .....

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The bullet connector is polished clean with a wire wheel in a Dremel and then coated with dielectric grease .....

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Then, after the switch contact plate is removed, I pull all the crimps out of the plug .....

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The original crimp on the brown wire is cut off and the "new" pigtail wire is added .....

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Then following an XSLeo tip, the wire end is brushed with some dielectric grease becore installing the crimp on it .....

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Now, before inserting all the crimps back into the plastic plug housing, the locking tabs need to be bent back up. The removal process flattens them down .....

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More dielectric grease .....

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And the finished product .....

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I did something similar but different, I bought a male and female plug and made a short loom in between the ignition plug and the main harness with a splice like yours 5Twins. difference is it can be removed and the original plugs put back together.
 
Could you wire it direct to the battery using the plug from your battery tender
 
I don't think that would be a very good idea. The power wouldn't be "switched" and the meter would always be on. It may take a few days but I think it would eventually run your battery down. That being said, I have made up a little portable voltage tester I can attach to the battery, just temporarily mind you, for testing purposes. It's just one of those cheap eBay voltmeters mounted if a little housing. It has the battery tender type plug on it and I also made up an attachment with alligator clips for batteries without the battery tender pigtail. A medium sized spring clamp from HF can be mounted in various different spots depending on what's available to clamp to .....

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The top position above works well on my Special, allowing me to clamp it to the helmet lock loop on the seat/helmet lock .....

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For my Standard, moving the clamp to a bottom mounting hole lets me clamp it to the footpeg bracket acorn nut .....

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5 different mounting holes for the clamp allow me to configure it for just about any application.
 
I have it to where I either just turn it off at the device or unplug it at the battery tender site
Wouldn't that give me a pretty good idea of charging rates being directly connected to the battery ?
 
Well yes, it would. It should give the best reading possible. If you have a voltmeter with an on-off switch then it would be fine, as long as you didn't forget to turn it off, lol. However, most voltmeters don't come with that feature. They're meant to be connected to a switched power source which would turn them on and off with the key.
 
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