Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: turn signal



I haven't carefully surveyed the turn signal behavior of all the
vehicles on the market, but in my experience I have noticed that a
single burned out bulb (i.e. a finite increase in circuit resistance)
can cause a turn signal flasher to flash a) significantly faster,
b) much slower, c) not at all, or d) with no noticeable change in
frequency depending on the particular vehicle and flasher in
question. Overall, with the cars I've had an association with, it
seems that case a) is a little more common than the other cases b),
c), & d), but that may be due to my limited sampling statistics.

If there was a short in the circuit I would expect that a fuse would
blow and that would open the circuit and shut off the flasher all
together.

My money is still on a burned out bulb on the left side. I hope Carl
will report back to us what he found out what the culprit is when he
finds out the cause of the problem.

David Bowman

-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@lists.nau.edu] On
Behalf Of Jerry Hester
Sent: Friday, June 04, 2004 9:14 AM
To: PHYS-L@lists.nau.edu
Subject: Re: turn signal

It is true that this may be a burned out bulb, but it may also be a
short in the wiring. In most vehicles, the interior light just doesn't
operate if the bulb is burned out. The flasher which makes the light
blink depends on the resistance in the circuit. A lower resistance
generally equals a faster blink rate.

Carl E. Mungan wrote:

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/




--
Jerry Hester
Jhester@mtu.edu
Laboratory/Lecture Demonstrations Coordinator
Department of Physics
Michigan Technological University
1400 Townsend Drive
Houghton, MI 49931-1295
Phone: (906) 487-2273
Fax: (906) 487-2933