[TR] TR3 Amp Gauge

Randall TR3driver at ca.rr.com
Sun Aug 4 10:31:38 MDT 2013


> What I mean is that the indicator light stays on.   The 
> battery is fully
> charged.   With the car running and nothing causing a 
> discharge, the light
> stays on and the amp gauge is at 0.  

The light should go off with the engine running at a fast idle (or above).
Sometimes it will glow at a low idle.

Most likely cause depends a lot on recent history.  But certainly doing a
visual on the wiring at the control box & generator is a good start.  The
wires at the generator end lead a hard life, and it's not unheard-of for
them to just break.  The wire from the large terminal on the generator
should lead to 'D' on the control box, and the small terminal connects to
'F'.  While you're there, grab the generator and try to move it on its
mounts.  Should be completely solid, any movement at all indicates a problem
(usually with the lower front mount).

There is a Lucas booklet at http://tinyurl.com/bab2hsc with methodical
tests.

If you've been working under the dash recently and think the lamp might be
wired wrong, a simple test is to disconnect the small yellow wire at the 'D'
terminal of the control box (or just both D wires if that is easier) with
the engine stopped.  The dash lamp should now stay out, with the key on or
off.  If so, the wiring to the lamp is probably OK (since it was on before).

If the generator has been off (or replaced), it's worthwhile IMO to try
repolarizing it.  Lots of ways to accomplish that, but since you have the
later control box with the quick connects, it's probably easiest to pull the
wire off 'F' and brush it against terminal 'A'.  You should get some small
sparks.  Then connect the wire back to 'F' and try it again.

-- Randall 


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