Re: turn signal

[Matt Coia <mattyc@WNYRCINFO.COM>]

Everyone is correct.  Most auto manufacturers use this old (but well
tested) method of telling the drivers there is a bulb out.  The flasher,
that's really what it's called, is replaceable like a relay.  When voltage
is passed through it and out to the bulbs, the plate or strip inside it
heats and causes the regular breaking of the circuit as bc said...but, it's
actually the LOWER resistance in the circuit, because of an absent bulb,
which causes more current to pass, faster heating of the strip and the
quicker flash rate.  Hope this helps!

Matt Coia
Undergraduate Assistant, Physics Education
Buffalo State College
oh...and ASE Certified in Automotive Electronics :)



> As of this morning, my left turn signal (1996 Toyota RAV4) is
> blinking about twice as fast as normal, about double the rate of the
> right turn signal. I've checked again just now after the car was idle
> a few hours and it's still doing it. Ambient temperatures and
> humidity have been pretty normal for the past day.
>
> So my questions are:
> 1. Is it a bad resistor, capacitor, chip, or what that might be doing
> this and any guesses about what might have caused it?
> 2. Is it something to worry about or, as long as I don't mind a
> double-speed blink, can I just ignore it?
>
> Thanks for any insights and I'd be happy to poke around under the
> hood with a multimeter if someone gave me a hint about what to try.
> Carl
> --
> Carl E. Mungan, Asst. Prof. of Physics  410-293-6680 (O) -3729 (F)
>       U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5040
> mailto:mungan@usna.edu       http://usna.edu/Users/physics/mungan/