Is that 8 volts on the negative terminal while the car is running or
with the engine off? if it's with the engine off, you've got a progblem
with either the points, condensor or ground connection on the
distributor.
jaltman@altlaw.com wrote:
>
> Well, I ran out bright and early before running off to work and the wire to
> the coil is plain white. I measured the resistance from the fuse block to
> the coil and, after cleaning the fuse to get good contact, read .2 ohms. I
> think I'll stop by NAPA on my way into work and pick up a stretch of 10 or
> 12 gauge wire and jumper the piece anyway.
>
> Also, I think I may have made a serious misstatement. Once I opened the
> hood I realized my recollection of the poles on the coil was backwards. I
> have 8 volts on the negative terminal, not the positive. I didn't want to
> wake the neighbors by running the car this early in the driveway while
> checking the + voltage, but I am sure it is in the neighborhood of 12.
> (Neighbors bedroom window is only about 5 feet from my drive.)
>
> So I guess this means we're back to the alternator? BTW, yes, this is a 69.
>
> Jim Altman jaltman@altlaw.com Illigitimi non Carborundum
> http://www.altlaw.com/metro/jaltman.html 69-TR6#CC28754L W4UCK
>
> -----Original Message-----
> From: DANMAS@aol.com [mailto:DANMAS@aol.com]
> Sent: Tuesday, September 29, 1998 11:08 PM
> To: Jim Altman
> Subject: Re: Have been chasing the wrong item?
>
> In a message dated 98-09-29 21:17:18 EDT, you write:
>
> > I noticed previously that the voltage on the plus
> > side of the coil, engine running, is only about 8 volts with everything
> off.
> > I had consigned that to the fact that the on/off cycle of the coil was
> > having me read something on the order of a sawtooth wave with Digital DC
> > volt meter. So I concluded I should read something quite a bit below
> 13-14
> > as I am sure I am reading average rather than peak volts. Are you saying
> I
> > should read 14 on the coil in spite of the duty cycle of the coil?
>
> Jim,
>
> I think we have found your problem. You should be getting the same voltage
> on
> the coil as you have on the battery. The duty cycle will not be seen on the
> positive post of the coil, only on the negative. The duty cycle will also be
> seen in the coil current, but even then, it will be confusing due to the
> nature of the coil/capacitor combination, and the fact that the current rise
> and fall in the coil is non linear.
>
> Evidently, the wiring harness has been replaced at some time, and a harness
> for a later model was used (yours is a '69, right?). The later models have a
> ballast resister built into the coil circuit, which will reduce the voltage
> to
> about 8 volts or so, too low for the sport coil. One quick way to tell -
> what
> color is the wire to the positive post ofd the coil? It should be white. If
> it
> is white with a yellow stripe, then you have the ballast resister.
>
> Or, perhaps, a separate ballast resistor has been added?
>
> Try this test. When the engine is idling roughly, with all the electrical
> accessories on, take a piece of wire and connect it directly from the
> battery
> positive post to the coil positive post. I'm certain the idle will smooth
> out.
>
> If it does, then we need to make a permanent fix, which is very easy to do.
> Simply run a wire from the positive post of the coil to the spare terminal
> on
> the fuse box where the white wire is attached. Just leave the existing wire
> attached to the coil.
>
> There may be an even easier way to do it than that, if your car has a
> starter
> relay. If so, just lift the white/yellow wire from the relay, and connect it
> to the spare terminal mentioned above. That's it! No other changes are
> required.
>
> Of course, things are not always as shown on the Triumph diagram, so you may
> not have a spare terminal at the white wire connection - there may be more
> than one white wire attached here. If so, you will have to make a splice
> connection, or get one of the "piggyback" connectors at the local auto
> supply
> store.
>
> For more info on the ballast resister, check:
>
> http://www.vtr.org/maintain/ballast.html
>
> Let me know what you find when you make the test.
>
> Dan
--
George Richardson
'57 TR3, TS15559L - painting and reassembling....
http://www.merlingroupinc.com/tr3.htm
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