[TR] TR3 Turn Signal Flasher Failures

Randall tr3driver at ca.rr.com
Sun Jun 16 21:05:46 MDT 2013


>      About every 3 years my TR3A turn signal flasher starts
> malfunctioning. It
> works fine and then one day it will work fine on the right turn signal and
> the
> left turn signal will flash one time and stop.

Sounds like for some reason, the LH signals are drawing less current than
the RH.  Bad connection, corroded wires, even a really old bulb might be the
cause.  Do they act the same with the headlights on?

(I'm guessing that, as the flasher ages, it takes a bit more current to make
it work properly.  That's why a new flasher solves the problem, for awhile.
The stock flashers are deliberately sensitive to current draw, so you can
tell when a bulb burns out.)

>      I bought a new "heavy duty" flasher unit from NAPA that
> looked similar, but the turn signal indicator doesn't work at all now,
> although the turn signals themselves work. It probably takes too much
> electricity to run or something.

I had much the same experience with all of the thermal 3-prong flashers from
Kragen (now O'Reilly).  They are simply not made correctly to work in the
circuit in our cars.  On the last one, I finally gave up and changed the
wiring to the dash lamp to make it work.  The change was simple, I just
removed the ground wire for the indicator lamp, and connected the wire to
switched 12v from the switch instead.

Later, I switched to a Tridon EL13 "electronic" flasher, which works with
either connection to the indicator lamp.  The first one failed after 5 years
or so, apparently because the mounting clip I used was too tight and the
plastic housing cracked.  But the second one is still going strong.

FWIW, the EL13 is not truly "electronic", it just uses a RC timing network
and relay instead of the usual resistance wire and bimetal strip contacts.
It should still work correctly with positive ground.

-- Randall


More information about the Triumphs mailing list