Voltmeter questions...

[bigsteveswing]

This my be a bit over thinking, but that's what I do.

What gauge wire would you use for a digital voltmeter?

Is it necessary to switch the power through a relay or can I just power direct from acc. terminals with a fuse? What size?

[WingAdmin]

This my be a bit over thinking, but that's what I do.

What gauge wire would you use for a digital voltmeter?

Is it necessary to switch the power through a relay or can I just power direct from acc. terminals with a fuse? What size?

Voltmeters draw a miniscule amount of current. You can use a small gauge wire. 18 or 20 gauge would be fine. Just make sure it is capable of carrying the current that can be supplied by the fuse it is connected to, or else the wire itself will become the fuse in the event of a short circuit.

You can power it from the ACC terminal with no problems, although you will read a half volt or so low from the resistance of various parts of the bike before the ACC terminal.

The ACC terminal is already fused. However you could put a small one, say a 0.5 amp fuse on the wire going to the voltmeter as well. That way you could safely use a much smaller gauge wire.

[AZgl1800]

I agree with Scott, although #18 is the smallest I would go, simply because of needing to protect a fragile piece of wire...

and a 1/8 amp fuse is what I would use.... I hate the smell of smoke,
have let a lot of "good smoke" out of electronics since 1958.

[bluthundr31]

You're definitely NOT overthinking this, , , its very wise and prudent to want to know what the old alternator is doing. I wish Mother-Honda had done more to see the need, and put a voltmeter on this model from the beginning. I'm sure every rider who has been stranded due to an alternator going south would agree with me.

What style/brand of voltmeter are you planning to install, , , and where??? A pic is worth a thousand words, , ,

[bigsteveswing]

https://www.amazon.com/dp/B010HM43RQ/?tag=goldwingdocs-20 ... .Cb81NQ7JP

This is the unit I bought. I am hoping to put it in the hole where the foot warmer control would be on an SE bike, I just have a plastic plug there now.

Thanks so much for the advice, I didn't know one could get a 1/2 amp fuse, let alone an 1/8.

[Snowmoer]

https://www.amazon.com/dp/B010HM43RQ/?tag=goldwingdocs-20 ... .Cb81NQ7JP


I didn't know one could get a 1/2 amp fuse, let alone an 1/8.

You are not going to find it at the auto parts store! You will need to go to a business that deals with electronics to find one. Your best bet would be E Bay or Amazon to find these low amp fuses. I have picked them up on both sites.

[bigsteveswing]

Would there be any problem running 18 gauge wire and a like a 3 amp auto style fuse? All the really low amp ones I find seem to be the glass tube type. I've never been a big fan of those.

[CrystalPistol]

Would there be any problem running 18 gauge wire and a like a 3 amp auto style fuse? All the really low amp ones I find seem to be the glass tube type. I've never been a big fan of those.

That'll work. With 18 ga wire, you could even use a 5 amp or 7.5 amp.

Are you coming off the battery or ACC terminal?

What's wrong with good old glass fuses anyway?

I use them, I even prefer them to spade or blade type fuses when I'm running a new circuit. Easy to push wire out a little to solder crimp if a high amp circuit, and then a wrap of tape on holder secures them well. They work, easy to diagnose for blown, and usually are in a spring loaded carrier. With a spade or blade style fuse holder, it is almost impossible to inspect crimp.
I like to put just a dab of dielectric grease on contact points, but not needed.

Really low amp ones have really fine wire links that are easier to protect in a glass tube. Looks like a hair.

I used a 2" Sun Pro Volt-meter on my 1200, but 1500 has Airider combination volt meter / gear indicator. Below is a test I did, comparing readings straight from battery a few years ago. There ain't much real difference.

[AZgl1800]

Would there be any problem running 18 gauge wire and a like a 3 amp auto style fuse? All the really low amp ones I find seem to be the glass tube type. I've never been a big fan of those.

that will work perfect, and 3 amp ATM fuses are common, as are 2 amp if you wish.

[bigsteveswing]

Would there be any problem running 18 gauge wire and a like a 3 amp auto style fuse? All the really low amp ones I find seem to be the glass tube type. I've never been a big fan of those.

That'll work. With 18 ga wire, you could even use a 5 amp or 7.5 amp.

Are you coming off the battery or ACC terminal?

What's wrong with good old glass fuses anyway?

Nothing wrong with glass fuses, I just personally like having one type of fuse in an assortment of ratings with me. I have some glass fuses in my car, just prefer blades. No real good reason I guess...

I am planning to just come off the ACC posts, was thinking of going direct to battery and switching with a relay. Consensus seems to be that I will show a small voltage difference, but the goal for the meter is to show massive change or unusual behavior.

[CrystalPistol]

I am planning to just come off the ACC posts, was thinking of going direct to battery and switching with a relay. Consensus seems to be that I will show a small voltage difference, but the goal for the meter is to show massive change or unusual behavior.

I did that a few years ago on both the 1200 and the 1500 trike, using ACC to trigger relay. In both cases, 1/2 volt or less difference, so …. not sure was worth it. If you go the easy way, no relay, you'll get used to a certain reading and be just as alerted to an issue arising I think.

[bigsteveswing]

Ok all, thanks for the responses but I may switch things up a bit.
If I go with this unit instead, will 16 gauge wire be ok or do I need larger? Still ok with a 5 to 10 amp fuse? I can't see anywhere in the description what wire gauge comes with it. Does say 10 amp guse though.

https://www.amazon.com/dp/B07PP7RLT9/?tag=goldwingdocs-20 ... aDbBC7RTVD

[bluthundr31]

If that voltmeter/USB port device is the only thing you put on the wire, ,you should be OK with 16 AWG, , put an in-line fuse just to be safe though. HOWEVER, , if you already have 12-14AWG that you can use for that voltmeter, , it might be a wiser choice. I'm hoping one of the "guru's" will be along shortly though, they are MUCH more knowledgeable/familiar with electrical needs than I am. BTW, , NICE LOOKING DEVICE!!!

[CrystalPistol]

Ok all, thanks for the responses but I may switch things up a bit.
If I go with this unit instead, will 16 gauge wire be ok or do I need larger? Still ok with a 5 to 10 amp fuse? I can't see anywhere in the description what wire gauge comes with it. Does say 10 amp guse though.

https://www.amazon.com/dp/B07PP7RLT9/?tag=goldwingdocs-20 ... aDbBC7RTVD

16 gage is aplenty, especially if you fuse at 5 amps. I may get me one of those, wire it to a male 12vdc plug, and then simply use in whatever I'm using, trike or car or PU. Maybe get the long one so I can still have a vacant 12vdc outlet, volt meter at device, and USBs?

[AZgl1800]

for a voltmeter, the gauge of the wire is immaterial.
what is important, is the wire's insulation so it won't be penetrated by bumping it with something sharp.

as for a fuse? for a voltmeter, anything over 1/8 amp will be just fine.

[T_birdman]

The mini Voltmeter is the way to go, but I went with this style because it not only has a voltmeter, it also has a USB charging port, and an on-off toggle switch built in! Works like a charm!

https://www.amazon.com/gp/product/B07F7 ... UTF8&psc=1

[Mh434]

All good advice above, but I'd also go with one of the previous suggestions as well - I'd run a relay, connected directly to the battery & triggered by any of the accessory wires.

The reason is, as WingAdmin mentioned, running off the accessory circuits will cause your voltmeter to read low, and different voltmeters (particularly inexpensive ones) may give wildly different readings. There's a LOT of wire running to the accessory panel, and a LOT of items running off it, so there's always draw...and the load & voltage can vary as you ride. In my case, the digital voltmeter reads an average of 1.4 volts below actual.

Unfortunately, it's not even consistently inaccurate as, depending on which items are actually taking voltage at the moment, the reading on my GL1500SE's cheap, Chinese digital voltmeter ranges between 0.6 volts and 1.7 volts below actual as measured at the battery.

That's a LOT of uncertainty. The NORMAL range of operation while the engine's running should be between roughly 12.8 and 13.8 volts....a 1.0 volt range. With an uncertainty factor of more than that range, it's not possible to appropriately measure your state of charge.

I have an extremely accurate digital VOHMmeter I use for testing. You DO need access to a decent one if you are to know whether the readings from your new voltmeter are even remotely reliable.

In a GL1500, with a famous propensity for marginal charging at best, accurate voltage readings are critical information.

With a relay, at the battery, there's almost zero measurable loss going to the voltmeter, so you'll know the ACTUAL voltage at the battery.

A relay is such a simple, and cheap ($3 - $4) addition, and the confidence factor in knowing what's really happening will be extremely gratifying.

Just my $0.02' worth.

[bigsteveswing]

Thanks everyone for the help. I don't know why this simple electrical stuff gets me so confused...poor little welder brain

If I decide to go the relay route, correct me if I'm wrong.
1. Wire from battery to relay
2. Wire from relay to USB/Voltmeter
3. Wire from ACC. terminal to relay
4. Wire from ground point on bike to relay
5. Wire from ground point on bike to USB/Voltmeter

Just a regular run of the mill 30amp 5 blade relay?
https://www.amazon.com/gp/product/B0748 ... 0DER&psc=1

Sorry if I seem like a dummy with this stuff... one of my best friends was like a genius with this wiring stuff and he passed away in April in a car accident. Makes me feel like I don't have a clue.

[AZgl1800]

pretty much you got it right, as long as, you sequence the wires correctly.

and yes, any relay will do the job just fine. the heavier relays are actually cheaper than the smaller ones, because they sell more of those.

[Mh434]

That would be correct. By the way, ANY wire that is only live when the ignition is on will work to trigger the relay. You'll likely find such a wire closer to the battery than the accessory panel, which makes routing easier.

Here's one wiring diagram I found that identifies the various poles by number (any relay you get will have these poles by these numbers):

This is a 4-pole relay, but 5-pole are common too. If so, it will have a pin labeled "87A". That pole is simply not used, so it can be ignored.

Hope this helps. I'm always nervous, so I always test before I install, using the relay to power up a 12V light bulb or something. That way I KNOW I've got it right, and all the mystery smoke stays inside the wires!!

[bigsteveswing]

That diagram is a huge help, I know this isn't that hard but I just want to try to do things right the first time (I'm too lazy to do them again )

[bigsteveswing]

Well I got everything installed and wired today.

Used a hole saw, slowly and carefully, to cut hole in the dash.

Everything works the way it should, relay switched power. Only thing I will have to watch is the voltmeter itself, may have to return it for a new one, the far right part of the 7 segment display seems to be buggy...but thats easy enough to swap out.

The USB ports do fast charge my phone so that's nice. I used a relay and socket from Amazon, an inline blade fuse holder and 5 amp fuse. Powered the relay direct to battery, switched from the Acc. terminals in fuse box.

[AZgl1800]

I see you fused it to relate to the charging current.
good thinking

[Mh434]

As I wasn't happy with the voltmeter I had on the bike, I just purchased another one (Amazon Prime Canada, https://www.amazon.ca/gp/product/B07J56 ... UTF8&psc=1 ). It's far cheaper in the US - https://www.amazon.com/12V-Car-Digital- ... ref=sr_1_1

Anyway, it purports to be waterproof (I've read that where the wires enter the back it's not, so a dab of silicone or something would fix that), and the numbers are large considering the small size of the unit. They're quite bright, too, although in direct sun they're hard to read. I'm going to make a small sunshade for mine (like a small version of the ones you can get for GPS units).

While it's not perfectly accurate (you can see the reading in the photo - the actual voltage at the battery was 14.2V, not 14.0V), it's pretty close. As you can see from the older, smaller one I took off, it was even less accurate - as much as .5V off. That's a LOT of error. The new one's only .2V off. I still need to take my own advice & wire it up to a relay, so it doesn't detect voltage drops from all the other items on the accessory circuits.

Anyway, here's a couple of pics. I didn't use the sticky-two-side tape provided. I used Velcro - that way, if I wish, I can pull it off & tuck it inside the fairing pocket without having to disconnect it.

The old one that I just removed....

...and the new one I installed in its place...

New voltmeter

[Wildwilly018]

You're definitely NOT overthinking this, , , its very wise and prudent to want to know what the old alternator is doing. I wish Mother-Honda had done more to see the need, and put a voltmeter on this model from the beginning. I'm sure every rider who has been stranded due to an alternator going south would agree with me.

What style/brand of voltmeter are you planning to install, , , and where??? A pic is worth a thousand words, , ,

My Alt pooched a few weeks ago and yes a voltmeter on my bike would have probably stopped me from being stranded where I was.