The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Dizerens5 on April 09, 2010, 02:55:31 PM

Title: Voltmeter
Post by: Dizerens5 on April 09, 2010, 02:55:31 PM

My R65 voltmeter must be connected some place wrong because on switching on the headlight with engine running the reading drops nearly 1 volt (but it does not change if an external voltmeter is connected direct to the battery). It seems the obvious place to connect it and simplify the wiring as well would be the clock lead which is direct to the battery. But then the voltmeter would be in circuit all the time. Would it matter? A voltmeter's resistance is very high but presumably not infinite. And I do have a very distant memory of a ride in an Austin Healey sports car years ago and noticing the voltmeter keeping its reading all the time. Or maybe it was just stuck. Any ideas please?

Title: Re: Voltmeter
Post by: Bob_Roller on April 09, 2010, 03:03:33 PM

The voltmeter wiring needs to be as close as possible to a battery direct wire, so no other circuits bring the voltage down as they are used .

Also, it needs to be a 'switched' power source, as if the voltmeter is left powered up , it will drain the battery down .

This seems to be a common complaint with BMW voltmeter installations, they always seem to read low .

Title: Re: Voltmeter
Post by: montmil on April 09, 2010, 07:30:37 PM

Depending on the vintage of your scooter's wire harness, reading voltage drop is common due to old, corroded wires and connectors. When I added relays and fresh wiring to my 1986 VW Cabriolet, the voltmeter showed a =1.5 volt gain. Brighter lights, too.

Monte

Title: Re: Voltmeter
Post by: Dizerens5 on April 11, 2010, 10:08:21 AM

 Thanks for information! Appreciated.