help with electric testing needed.

[Janet]

Some of you will know that Vesta was somewhat lacking in the illumination department out on the Westward Ho! run last weekend. This was slightly inconvenient as most of the ride is at night. I have now started checking my electrical system an attempt to discover the source of the problem and, hopefully to find a cure.
In the manual it says I need the following:-

0-12 dc voltmeter
0-15 ac voltmeter
1-ohm resistor
10-0-10 dc ammeter

I have a multi-meter that I'm guessing will do for the volts bit.
I only have an 8-0-8 ammeter
Where I'm scuppered is with the resistor. Please will someone tell me what will be suitable and where I can get one from. If I already have one lurking within my wiring, I'm perfectly happy to be proved an idiot.

Also, in the instructions it says
1) disconnect the white, light green and orange wires from the four way connector.
2) Using the ac voltmeter, with the one ohm resistor across the terminals (parallel) join one wire from the voltmeter to the white wire, the other meter wire to the orange wire. Run the engine.............. then repeat with the meter between the white and light green wires.

To help me get this right in my mind, does this mean the resistor connects between the white and orange in the same way that the volt meter does?

I'd be very grateful for any help with this.



Every day's a school day.

[Expat]

Hello Janet.
Have done much similar testing as you propose but sorry, I don't understand the details enough to be of much help to you now as I just followed advice mainly given here and readings obtained may differ between our bikes anyway.

I'm sure much help will be forthcoming soon to allow a little (or more!) light into your life.
Regards
Steve

Edited to add that in my case, the answer was to fit led lights and a modern rectifier/regulator.

Good luck.

[Harry44]

Hi Janet a 30 watt 6 volt headlamp bulb draws 5 amps. volts = amps x ohms so 6v = 5 x not much i.e. about one ohm

and yes connect the resistor (bulb) across the same connections as the voltmeter.

[Janet]

That's beginning to make sense. From my school days I could remember volts x amps = watts and there was some formula that was V=IR but if V = volts, R is probably resistance but I couldn't think what 'I' represented. So it's current, spelled Iurrent. That make life so much easier. It appears that I already have several of these resistors in my box of bits so I am an idiot.

Thanks, teacher.

[Harry44]

My pleasure.

[Rob Harknett]

I = current in amps. R = Resistance in ohms, Janet. Cannot help much with alternators and coil ignition. I have 3 light weights myself with electrical problems I cannot / have not cured. Have to do something soon as twins and heavy weights are getting too heavy for me to handle. THat only leaves me my much lighter pre war bikes.

[ajscomboman]

Janet, ignore the requirement of requiring a resistor. Go to the archives and search in the technical area for an article by Al Osborn about testing alternator stators and rotors.

The resistor is a wire in the harness if you have the original loom. Its the clear sheathed wire and it's length is critical to regulate charging. If you have a replacement loom by Colin F then it maybe in the headlight and is a ceramic type block. That aside, to check the charging simply set your meter to 50V DC start the bike and place the probes on the battery terminals if all is well you should see 6.5V min and revving up the bike it should raise to 7.5V approx indicating the alternator is ok. The problem with the headlight is then likely to be earth related.

[Expat]

Janet, ignore the requirement of requiring a resistor. Go to the archives and search in the technical area for an article by Al Osborn about testing alternator stators and rotors.

Here 'tis


http://archives.jampot.dk/technical/Ele ... _Testing__(Al_Osborne_in_Jampot_October_1996.pdf

[Janet]

Thanks chaps.

[Ozmadman]

Get rid of the resistor wire in the headlamp as that caused nothing but trouble in the bulb blowing and battery boiling department and the old regulator and get an A REG (resistor/regulator)from Paul Goff, easy to fit, no more bulbs blowing and excellent charging. Had one on my bike for 4 years now and no issues.

http://www.norbsa02.freeuk.com/goffyelectrex.htm