In a message dated 98-10-19 20:53:45 EDT, carbuff@nac.net writes:
> The circuit path for the turn signals goes 'through' the hazard (4-way
> flasher) switch. If the hazard sw. contacts offer up a high resistance, the
> turn signals can operate slowly or not at all.
>
> Actuating the hazard switch periodically keeps the contacts clean and the
> turn signals working.
>
> Of course, it's the ignition switch that affects all that other stuff
> (radio, instruments, etc). The hazards operate independant of the
> ignition switch, but the turn signals won't work until the ignition is
'on'.
>
> I have heard of several 60s and 79s Lotuses that have been cured of weird
> electrical ailments by replacing the ignition switch. And you wouldn't
> have to take that dashboard apart again, would you? :)
>
> Atwell "I'm no Dan Masters" Haines
Atwell,
You did well! A very good explaination. I would only add one thing to it, and
that is the reason the turn signals receive their power through the hazard
switch. On the surface, this seems like a silly idea, but there is a very good
reason for it.
Unless the designers had the luxury of using separate bulbs for the hazard
flasher and for the turn signals, both circuits connect together at the bulbs,
The hazard flasher is intended to wqork all the time, key on or not, while the
turn signals are designed to work only with the key on. If the hazard switch
didn't isolate the turn signals, power would back feed through the common
connections at the bulb, and current would flow back through the turn signal
switch to the ignition switch. When this happened, every thing that is powered
by the ignition switch would receive pulsing power from the hazard flasher,
and these items could turn on-off-on-off with the flashers. Not only is this
annoying, but the turn signal wires are not sized to carry all that current.
Here's the scenerio: You are driving along on a cold rainy, night, heater fan,
wipers, and the radio playing. You hear a noise from the back of you car that
doesn't sound quite right, so you turn on the turn signals and pull over to
the side of the road, and turn off the key. There was no reason to turn every
thing off, because the key did it for you. Now, for safety sake, you turn on
the hazard flasher, but you didn't turn off the turn signal. Immediately, the
wipers, fan, and the radio start pulsing on and off. I had a '68 Plymouth
that would do just that. The designers added hazard flashers as part of the
Governments regulations, but didn't think to isolate them. These were
Chrysler designers, not Lucas!
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/index.html
'74 MGBGT---3000mile/year driver, original condition - slated for a V8 soon
'68 MGBGT---organ donor for the '74
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