[TR] '3a Alternator conversion...

Randall tr3driver at ca.rr.com
Tue Jun 15 09:59:47 MDT 2010


> (where I've had more problems
> with alternators than with generators)! :-)

Well, I supposed I should weigh in on the other side of this.  "Back when" I
went through several Indiana winters with a TR3A as my only car, and found
the stock 19 amp generator to be totally inadequate.  The only upgrades were
H4 headlamps (55 watts as I recall) and a rewound heater motor.  With
everything running, I measured the total load at over 20 amps, meaning that
not only would the battery never recharge from starting the engine (which
took a lot after sitting outdoors overnight) but it would slowly run down
while driving down the road!

I worked second shift at the time, only about 5 miles from work, so
generally I drove with only headlights (no heater or wipers) both to and
from work.  But there were traffic lights, and the generator doesn't put out
much of anything at idle.  A fully charged battery would last only a few
days of this before being too weak to start the engine.  I got to be an
expert at push-starting the car by myself; but it still wasn't exactly what
I wanted to do at 12:45 AM so I could go home to bed.

After installing a Ford alternator, the TR would start even when other cars
would not!  It was the source for jump-starting American cars more than
once.  And the junkyard alternator I installed outlasted the car.  Like
night and day, especially considering that for a time I was burning up a
generator every month or two (from trying to get too much current out of
it).

The alternator setup worked so well that I duplicated it on my next TR3A
(that got wrecked a few years back).  In 20 years and over 150,000 miles, I
replaced the regulator once (with a solid state version), and the alternator
once.  The originals were $20 from a junkyard (including the wiring between
them); the replacements were around $60 as I recall (for both units, but of
course some 15 years ago).  With the 60 amps available, I also had power for
an electric radiator fan, high power headlights (120 watt H4), and a stereo
loud enough to be heard on the freeway.

I've been running an original generator on the "current project" TR3 for
about a year now, just to refresh my memory of what it was like.  I drive
farther to work, mostly freeway and mostly in the daylight, so it's been
much less of a problem than in those cold Indiana winters.  Still, I've had
a couple of dead batteries in the morning; and I just installed that old
electric radiator fan ... so there is a nice shiny "mini" alternator sitting
on the shelf waiting for me to build a "hot rod" motor to go with it <G>

Randall


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