[TR] TR4 generator failing

[Geo Hahn]

On 4/22/10, Lee&John Howard <leejohn7 at gmail.com> wrote:
> Would someone be so kind as to describe a simple voltage test that I can
> conduct at the generator, so I can be certain I have that right?

Possibly this will help (from a long-ago post, imagine an organ riff
as used to tell radio listeners that a flashback is coming)...

1.  Verify that the battery is in good condition.

2.  Verify belt tension is okay.

3.  Test the Armature -- Disconnect dynamo leads and check voltage at
the D terminal (the big one) at 1500 RPM should be 1.5 - 3.0 V.

4.  Test the Field -- Leave voltmeter as above and connect ammeter
between D terminal and F terminal (the little one).  Increase engine
speed until voltage is about 12V, ammeter should read about 2 amps.

Haynes offers a variation on the above -- you disconnect the leads and
connect a jumper wire between D & F. At idle the dynamo should then put
out about 15V.  They indicate that a reading of 0 suggests the brushes
are faulty, about 1V suggests the field is faulty, 4 to 6V suggests the
armature is faulty.

Geo