I posted this a week ago or so, so it may look familiar to some.
To test the coil for internal resistance disconect all the wires going to
the coil. Set your multimeter to the lowest ohms scale. Now with the meter
connected to the + and - side of the coil you should get a reading of
about 1.5 to 3 ohms. Much higher or lower indicates a bad coil. Next check
the secondary circut. Set the meter to the high scale and put one lead on
either the + or- terminal. Put the other lead into the tower at the top
of the coil. You should get a reading of between 6,000 and 30,000 ohms.
copy this reading down along with the scale you got it on. If your coil
turns out to be good you can use this reading in the future when the coil
may again be in question. This will be your bench mark. The last test that
you need to do is for an internal ground. Set the meter to the high ohms
scale and connect one lead to the + or - side of the coil and put the
other lead onto the case of the coil. The needle should not move at all.
If it does there is an internal ground and the coil must be replaced.
If you want to check the condenser there are a couple of ways to
do it. Disconnect the small wire and make sure it is not touching
anything. Set your multimeter to the dc scale and measure the voltage from
the disconnected small wire to the to the screw on the distributor that
the wire is normally connected to. If you get any voltage the condenser is
bad. The other way involves using a screw driver on the points while the
condensor is disconnected but I won't go into it now because I don't want
to run on and on and...
...Art
On Thu, 7 Aug 1997, Steve Tritle wrote:
> Arthur Pfenninger wrote:
> >
> > Open the hood and take a look at the spark plug wires and coil in
> > the dark. You might also want to spray a little water on them, you may
> > have a bad wire or coil. Also did you clean the cap?
> > ...Art
> >
> > On Wed, 6 Aug 1997, Steve Tritle wrote:
> >
> > > The TD has been running great for 2500 miles. Went out for a spin and
> > > got a "rough" running engine. I decided to check the points and they
> > > were pitted so I filed them smooth. Started and still not quite right.
> > > So now I am changing condensors. Each of three condensors do not do the
> > > trick. Could the points need replacing or maybe even the coil? I had no
> > > problem with the car one day and the next day I started it up and it
> > > will not run well. I did clean out the carbs, filter at fuel pump etc.,
> > > etc. The timing is right on the mark and the points are gapped to .o11.
> > >
> > > Coil or points or maybe even a fourth condensor? What do you think?
> > >
> > > Steve
> > > 52 TD
> > >
> How can I tell if the coil is bad?
> Steve
> 52 TD
>
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