On Tue, 29 Jun 1999, Rob Christopher wrote:
> He actually has a bench mounted test jig he built so the alt isn't in the
> car. I'm not exactly sure how he's got the IGN connection wired as I wasn't
> there when he tested it.
I would suspect that it's correct then ;-)
> But to throw some more info at you, the whole reason I pulled the alt and
> battery for testing in the first place (besides the < 11 volt reading on the
> dash) was the little red IGN light in the tach would come on while idling and
> go back out when rpms went above 2000 or so. The headlights would also
> brighten above that 2000 rpm mark so I think the alt worked, although
> marginally, at that point. When he opened the case, he found the brushes
> were non-existent, ie the srpings were actually making the armature contacts.
Yes, "red light fade" is a symptom of worn/missing/stuck brushes. I had
this happen to me on my faithful, yet now departed, Chevette.
> I'm almost wondering if it's just his test setup and that if I drop it back
> into the '6 that it'll be fully functional. He's used to testing/rebuilding
> Lucas units, do they have this same bootstrap requirement?
It would be worth a try. I have to 'blip' the gas (up to 2500 RPM when
cold) to get my Chevy alternator to start charging. Sometimes even the
Chevette required this. I think it may be a symptom of old electrical
systems (... corrosion in the system somewhere, failing components, ye
Lucas Gods at play). When the TR4 is warm, the magic red light will
usually go out without any encouragement from me. I've been tooling
around at night, heater on, stereo on, wipers on, hi-beams, etc.. with no
sign of any trouble. Sometimes I get a bit of a glow from the red light
but I think that's a voltage imbalance between either side of the test
pole, and not a sign of a failing alternator.
The phenomenon, call it what you will, seems to be caused by having 14V at
the alternator and 12V at the battery, and a light bulb connected between
each. 2V difference = dim bulb.
If you mechanic had to bootstrap the alternator (if it's like a Chevy
one...) by shorting out the tab on the voltage regulator-- done by
sticking a screwdriver in the Appropriate Hole and grounding out the
Appropriate Tab (thus bypassing the voltage regulator), then all I can
suggest is that it may be a broken voltage regulator. However you got a
new diode set so that doesn't make much sense to me.
I intend to solve my slight problems with the alternator by having a
slightly smaller pulley fitted. That's one of the things I have simmering
away on the back burner though- it ain't broke, so I ain't fixing it.
-Malcolm
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