I wrote > >
> > A car having two dashboard indicators just has them hooked up in parallel
> > with the outside lights.
Roland writes >
> The rear exterior lights and dash indicator on my snake are connected in
> series. Yup, this kinda surprised me too. Maybe this was the only
> way AC could figure out how to do it with a two-prong flasher.
Could be, see below. They may have done this so that if you burn out a rear
bulb, you will know it, because the dash indicator for that side won't work.
There are a couple of problems with this theory.
If your dash bulb burns out, the rear bulb won't light.
There is no indication when the front bulb goes out. The front left light
is the most important (in countries wherein one drives on the right side of
the road) signal. The left right is at best worthless and at worst a
liability (There was a traffic safety expert named Smith that actually
advocated breaking the bulb on the right front. Gets a lot of people mad
at you, but does not cause any accidents.)
Actually, I should not say there is NO indication if the front bulb dies.
Just not the same as the total loss of indicator function as the rear
failure causes.
In a NORMAL two-indicator system, the warning that you have lost a bulb is
when the "on" time for the light gets longer. Since you have only one two
bulbs being powered instead of three (and the dash indicator does not draw
as much anyway) the current flow drops by perhaps 40%. The bi-metal takes
longer to heat. The "off" time should be about the same. In some cases,
the current flow of all the bulbs was marginal, and if one burns out, the
current is not sufficient to heat the bimetal enough, and the lights will
all glow without flashing.
In a normal one-indicator system, the warning that you have lost a bulb is
when the "off" time for the dash light gets longer. Remember that the
dash light is out of phase with the outside lights. In some cases,
the current flow of the outside bulbs was marginal, and if one burns out, the
current is not sufficient to heat the bimetal enough, and the outside lights
will glow without flashing, and the inside indicator will not come on at all.
Back to Roland's observation (I digress sometimes).
> The rear exterior lights and dash indicator on my snake are connected in
> series. Yup, this kinda surprised me too. Maybe this was the only
> way AC could figure out how to do it with a two-prong flasher.
I assume you mean that there is only one dash indicator. This is really
weird. You mean to say the single indicator on the dash is in series with
the rear lights but not the front lights? This is going to be more
difficult than if the front ones were included, IMHO. You could have the
battery feed the dash indicator feed the control feed the outside lights
in parallel with each other. Only a single-throw flasher (two prongs) is
needed. All the lights go out if the dash indicator fails. Indicator
fails in "left" if both of the left bulbs burn out.
OR
Are the rear lights grounded normally? If not, this setup would work:
Battery goes to control lever goes to outside lights. The front lights
ground normally. The rear lights go to the dash indicator which goes to
ground. If the dash indicator burns out the rear lights don't work.
This is weird enough for most people. Hard to believe that itwould
not be just as cheap and easy to use either two dash indicators or a
three-prong (double throw) flasher.
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