In a message dated 10/15/2006 5:11:36 PM Central Standard Time,
kehrlich@syntapharma.com writes:
> Yesterday the ignition light suddenly went on while driving and the
> voltage guage reading 11+ . I thought the alternator was shot, though it
> was only about 500 miles/1 year old. I drove about a mile and shut it
> down ( at my office fortunately).
>
>
>
> I changed out the alternator to another one I had, which I had taken out
> because it seemed weak, not because it was absolutely not working.
>
>
>
> No difference-ignition light on, volt guage 11 ish.
>
>
>
> Today I put the multimeter on the battery without car on and I am
> getting 12 + volts.
>
>
>
> I removed the alternator plug, started the car and put the multimeter on
> the live terminal of the alternator and it read somewhere around 17
> volts output. That seems to mean its putting out plenty of electricity.
>
>
>
> I plugged it back in and let the car idle for about 20 minutes. I put
> the multimeter on the battery with the engine running every 5 minutes or
> so and there was no discernable drop in voltage ( it read between 11.95
> and 11.93 volts). I would think idling the car this long on battery
> would kill the battery-and this one has to be at least 8 years old. So I
> got thinking maybe the alternator was keeping the battery charged just
> fine and maybe there was some other problem in the wiring. I had
> dissected the dashboard some months ago and I wonder if a wire in the
> ignition-voltmeter-battery circuit came loose or got grounded somehow
> which is giving the false reading of the light and guage. But the
> strange part is that if I remove the ground wire from the neg terminal
> of the battery, the car shuts down, which would then seem to indicate
> that in fact it is not charging. Or there is some freak thing happening
> to the wiring in the dash.
>
>
>
> Anyone have any ideas before I have it towed home? I've been through the
> TR6 Electrical Manual and all it says to me is if the ignition light is
> on, then its not charging.
>
>
>
> Thanks for any help.
>
>
Idling the car draws very little power from the battery. Even driving draws
very little. The ignition system draws about one amp. The battery, if fully
charged, will support that load all day and all night and well into the next
day. I drove my TR8 from TRF home (600 miles) with a non-functioning
alternator on battery power and it has an electric fuel pump. (I did buy a
spare
battery but my normal battery was pretty well drained)
The 73-76 TR6 has a power tap on the battery cable where a number (3) of
brown wires connect to the power source. I suspect there is a dodgy connection
there. Unplug the wires and replug them and see if that changes anything.
BTW if the battery was taking any charge at all the voltage would be in the
13.5 - 14.5 volt range.
Good luck.
Dave
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|