The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: alanp on 13.02. 2010 10:08

Title: Basic dynamo check?
Post by: alanp on 13.02. 2010 10:08
Without taking the 6V dynamo off the engine of an A10 and equiped with a multimeter how do I check the output of the dynamo? Do I take out the D & F wires, replace them with a bridge wire across D & F, connect the multimeter set at 20V from the bridge wire and earth and start the engine? If so, how many volts should I expect to see at say a fast tick over (2000rpm 'ish).
Thanks, Alan.
Title: Re: Basic dynamo check?
Post by: MG on 13.02. 2010 10:20
Alan,
your test set up is absolutely correct. The reading on the voltmeter should not exceed 10V and should rise steadily, fast and without fluctuations. Around 1000 engine rpm are usually sufficient to achieve 10 Volts.
Title: Re: Basic dynamo check?
Post by: mrshells on 13.02. 2010 11:25
thats the way to do it my 6v dynamo gives me 12 volt at about 1000rpm
Title: Re: Basic dynamo check?
Post by: Triton Thrasher on 13.02. 2010 12:32
Or connect a headlamp bulb between your bridge and earth.  Should light brightly by around 2000rpm.

I like that test because I know that if it can light a headlight, the dynamo is fit for purpose.
Title: Re: Basic dynamo check?
Post by: alanp on 13.02. 2010 16:11
Quick replies from Austria, England and Scotland, thanks.