triumphs
[Top] [All Lists]

TR3A Generator

To: triumphs@autox.team.net
Subject: TR3A Generator
Date: Sun, 27 Jun 2004 08:25:24 -0400
Hi all - finally got the TR3A running last weekend, and since replacing the 
brake system, was able to drive it for the first time! (Needs a few more 
things, like exhaust, lights, etc. before I can put plates on it, so just a few 
very short trips on the street in front of the house... but driving, 
nonetheless).

Before tuning the carbs, I verified the ignition bits were new/OK 
(plugs/points/condenser) and set the timing with a static light... (the vacuum 
advance dial seemed to have no effect).

Balanced the air intake, running pretty smooth, but rich. Shut it off to let it 
cool down, and fetch the right wrenches for the jet adjustment, and then it 
wouldn't start! ( Had been kicking over with a 2 second push of the buttoin 
previously).

Rechecked fuel supply, and determined it was an electrical problem. After 
messing around with everything ( re-installing the old point/condenser, 
checking spark at coil, distributor, etc. found I was usually getting a weak 
yellow spark at the plugs. Finally got it started - running REALLY rough, and 
tried adjusting the timing again.

To make a long story just a bit longer, since charging the battery overnight, 
and now it starts nicely immediately ( still somewhat rough), I'm now looking 
at the generator and/or voltage regulator. 

I found a post with test method, but have a dumb question - with the generator 
disconnected, I'm assuming the #3 and #4 tests are done at the leads which were 
connected to the D and F terminals, not on the terminals themselves?

TIA and the post referenced follows below

Cameron Joyce
'59 TR3A - getting there...
'54 TR2 deferred project

Here's the post:
Quoting from the book of Lucas, the tests are...

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 Hahn





<Prev in Thread] Current Thread [Next in Thread>