Connecting Volt Meter

[marcmax]

I am getting ready to add a volt meter to the instruments on my R65. No special reason other than I have it in the garage, the information it provides is handy and I like to see needles moving when I ride. Anyone have a recommendation on where do get + and where to ground it. I guess I could go directly to the battery since it lives on a battery tender when its in the garage. Suggestions?

[Crossrodes]

Marc I would go directly to the battery.

[Bob_Roller]

Only problem with wiring it directly to the battery, is that it is powered all of the time, eventually it will wear down the battery if the bike isn't run for a few days .

You need a switched power source, one that power is off when the key is turned off .

[ukzknos]

Wire the +ve to the green and black wire that comes from the right hand switch gear and pick up a battery earth for the -ve

[marcmax]

Thanks to everyone for the input. I like the idea of getting the + from the right side switch and a battery ground. Think that will be my weekend project.

[NorR65]

Does not the wire harness have a plug connector specially made
for connecting OEM BMW voltmeter?
I found a free connector plug under the instruments.
I am not sure if this is the right one.

[Bob_Roller]

My '81 doesn't have a convenient connector for any additional instruments like a voltmeter or clock .

That may be a different story, with bikes made for the European market .

Can you tell what color the wires are ?

Here's what a wiring harness looks like for the additional indicators, don't know how it connects to the bikes wiring harness .

http://www.realoem.com/bmw/showparts.do?model=0364&mospid=47851&btnr=62_0218&hg=62&fg=15

[Crossrodes]

Marc, I don't know what I was thinking.  Bob is absolutely right about connecting it to a source that has 12 volt switched on and off with the key.

I have a wiring diagram for my '79 R65.  Let me know if you need it and I will see if I can find a way to transfer it to you.  If your bike is not a '79 the diagram may not apply.

[NorR65]

My R65 from 1981 was imported from England to Norway.
The last page in Riders handbook is a wiring diagram.
Connection no. 47 described as connection for voltmeter is 2 green and black wires. This wire seems to be connected to the front brake light switch.
I can check have a look at my bike tomorrow.

[marcmax]

Thanks to everyone for their input. This is not an oem voltmeter but a vintage vdo meter. I don't  have a problem with a direct to the battery connect since I always connect a battery tender when it is parked in the garage but I like the idea of a switched power lead to the gauge. The suggestion of tapping off of the right hand (kill switch) I think is a good solution. I can always use the kill switch to disconnect power to the meter if necesary.

[Bob_Roller]

The kill switch is 'downstream' from the ignition switch, when the ignition switch is off, there is no electrical power to the kill switch .

[Semper Gumby]

HI Marc,

I connected straight to the battery but I installed a small relay from Radio Shack that is wired into the electrical system that only turns on the voltmeter when the ignition is turned on.

I forget what the part number is but it was in a drawer of electrical parts.  Small blue cylindrical relay that doesn't draw too much.  I installed it on a bit of hobby electrical board.  It lives in the fairing next to the voltmeter.

About 5 years and counting.

[NorR65]

For Bob Roller
The wires is indeed 2 black and green wires. I found the connector between the speedometer and tachometer after I removed the lower part of the instrument housing.

[Bob_Roller]

I just went out to my '81, as I vaguely remembered a 'spare' two wire connector around the indicator area .

There's a two wire connector with green wires with a black spiral band .

So we do have a convenient place to wire a volt meter to .

Thanks for the info !!!!!!

Mystery solved for the unused connector  wondered about that for years !!!!! .

[Bob_Roller]

The owners manual that I got with my '81, is for a 79-80 model year bike, this connector is not on the wiring diagram .

Just got home from work, checked the wiring diagram from the '84 LS, it shows  the connector and also on the page that describes what each numbered item on the wiring diagram is, it says the two wire connector is for an additional voltmeter indicator .

It taps off of the wire going to the front brake switch .

From the looks of it, the two wires go to a voltmeter and clock .

29 years of owning this bike, I'm still learning things about it .

This connector could also be used for a GPS unit, don't have to run a wire from the battery  .