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81 BMW r100rt volt meter died

johnpike

New member
I just went for about a 75 mile ride on a 1981 r100rt and right when I was parking and still idling I noticed the volt meter light died, and the needle was at 0. I turned the bike off and when I turned the key back the light and needle worked for just a second. Never came back on.

Any idea what may have caused this?
 
I just went for about a 75 mile ride on a 1981 r100rt and right when I was parking and still idling I noticed the volt meter light died, and the needle was at 0. I turned the bike off and when I turned the key back the light and needle worked for just a second. Never came back on.

Any idea what may have caused this?

Loose connection ?
 
Hopefully it's that simple, I'll check when it's light out! When I first thought of that, I thought it would be weird to intermittently come back on, but I guess it could have just wiggled the wire back into place for a second.
 
I didn't wait until it was light and wanted to check it anyways. It is just a bad connection but unfortunately it looks like the blade connector came out with the post it was connected to. I'll probably have to pull the gauge out (somehow) and see if I can solder it together.
 
How do I get the meter out so I can look at the back of it? Does it bolt in somewhere? Or is it screwed together by the front piece and some big nut? It's so hard to see or get under the trim/ dash piece it's mounted in.

I may just order the VDO while I'm at it and save myself the trouble soldering the old one back together. This one reads about 1.5 volts too low anyways.
 
It can be difficult to get in there, but try a mirror and flashlight so you can at least get a visual on things. But it's basically a u-channel which is secured by a nut on a stud that sticks out the back of the meter. That u-channel pulls the meter down and clamps against the inside of the fairing. The parts drawing will help a bit, too.

https://www.realoem.com/bmw/enUS/showparts?id=0449-USA-02-1981-2474-BMW-R_100_RT&diagId=62_0226

You basically come at it through either of the fairing side openings or "glove box".
 
Ok maybe I'll get a mirror and a tiny wrench. I just got this bike from a member who had laid it down, but apparently what he described as just damage to the fairing paint and plastic also bent the subframe that holds the top part of the fairing. I'm guessing my feeble attempts to straighten it resulted in me hitting the wire and making it lose, or of course it could have just vibrated out!

The next project is to strip the whole fairing down and replace the headlight bracket that holds to get it back to normal, seems like a big project to get everything off!
 
Itty bitty knurled nuts

The fich picture in the previous thread shows the two little plastic knurled nuts on the back of the meter holding the bracket in place.

Once you get the bracket off, the meter pulls out from the front of the dash.

It is a tight spot if you have big hands and a bit of colorful technical language may ensue during removal and replacement. Overall not difficult to do.

One tip if you have someone to help you is to remove the parking light above the head light and the helper can guide you by looking in the back of the dash.

Unlike the clocks, the volt meters seem to be cheap and plentiful on the used market. St.
 
If you have the OEM holder the nuts are thumb nuts no wrench needed. The VDO used a round backer that screws right to the back of the meter once its in the hole.
 
Mine was the oem and the nuts just twisted off. I just fixed the wiring on it by using a blade connector pigtail I fashioned. I’m traveling and spending a couple months away from home so I didn’t want to mess with it much more! Working fine now.
 
volt meter

The volt meters on the airheads are pretty bullet proof and long lasting.

While not 100% accurate, they do give an indication of the health of the charging system along with the indicator light.

Glad it was an easy fix. St.
 
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