James A. TenCate writes:
>what happens to a car if the ballast resistor or coil goes bad???
>How can you tell?
The ballast resistor is the fun one. The ballast resistor is there
to drop the battery voltage, so that the coil won't "saturate"
(so it won't become too magnetised). When you start the car the
ignition switch usually bypasses the ballast resistor to provide
lots of "oomph" to help ignite the fuel.
Try disconnecting your ballast resistor. Try starting your car.
Quite a few cars will notice that the car starts, but then (when the
key is released to the "run" position) the engine dies (no spark).
Makes a great anti-theft system !
To quickly check if your ballast resistor is bad, see if you can start
the engine - hopefully yes - see if the engine continues to run after
you release the ignition switch (or starter button !). If it dies, try
shorting out the ballast resistor - does your engine seem to be ok ?
if so, then your ballast resistor is bad. Try not to run your engine
without a ballast resistor for too long, I believe it is bad for the
coil - but then again, if it gets you home, who cares ... :-)
The coil can slowly deteriorate so that it doesn't provide an adequate
spark to keep the car idling, and mis-fires at high RPM. The car still
runs, but it's actually more of a limp than a run. Eventually it fails
completely. To quickly check if your coil is bad, replace it with a coil
(from just about any car) and see if it runs better.
>What exactly goes bad in a coil?
Good question - I don't know. It could be the "core" in the coil becomes
permanently magnetised in some way, or less succeptable to the magnetic
field the primary winding creates. Or the windings could "short out",
making them less effective, or ... hmmm
--
John Barlow, Parallel Computing Research Facility, I-Block,
Australian National University, Canberra, 0200, Australia.
email = John.Barlow@anu.edu.au
[International = +61 6, Australia = 06] [Phone = 2492930, Fax = 2490747]
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