Weird wiring for a weird car

OK, I am pretty sure it doesn't matter what specific car I have, other
than that it is a 12 volt negative grounded vehicle, with a separate
alternator, regulator, but I'll go ahead and say it... this is a 1971
Citroen 2CV.

Here are the two things I think are weird. The first may not be an
issue, because I haven't tested any other cars to see if they do the
same thing, but instinctively I think it's not right. When I put
connect a test light from the postive to negative battery terminals,
with the ignition OFF, the light lights up. When I turn the key, so
ignition is ON, but the engine is not running, the test light does not
light up. That just seems wrong to me, as if the ignition wasn't
grounded or something. But you experts tell me.

The second thing, that is more at the heart of the problem I'm having
(charging system not charging the battery) -- is this. With this car,
ignition OFF, the alternator's + terminal should have power, and
indeed, the test light lights up. And, both the Field wire on
alternator, and Field and Ignition wires on regulator all do NOT light
up with ignition OFF, engine OFF.

However -- with ignition ON, engine OFF, all FOUR of those wires light
up! -- though, I would estimate that the + terminal of Alternator and
the Ignition wire of the regulator are getting more volts than the
Field wire on both Alternator and Regulator, because the light is
brighter on the + or ignition wires.

Now, someone advised me that in that last scenario, ONLY the Field
light should be on unless the battery is discharged (granted, which
mine probably is), but I still think there's something screwy going
on.... My next step is going to be bypassing the harness and connecting
wires directly between Regulator Field and Alternator Field, and
Regulator Ignition to Battery Positive Terminal.

Any tips/suggestions/name calling?

Thank you,

Will wrote:
> OK, I am pretty sure it doesn't matter what specific car I have, other
> than that it is a 12 volt negative grounded vehicle, with a separate
> alternator, regulator, but I'll go ahead and say it... this is a 1971
> Citroen 2CV.
>
> Here are the two things I think are weird. The first may not be an
> issue, because I haven't tested any other cars to see if they do the
> same thing, but instinctively I think it's not right. When I put
> connect a test light from the postive to negative battery terminals,
> with the ignition OFF, the light lights up. When I turn the key, so
> ignition is ON, but the engine is not running, the test light does not
> light up. That just seems wrong to me, as if the ignition wasn't
> grounded or something. But you experts tell me.
>
> The second thing, that is more at the heart of the problem I'm having
> (charging system not charging the battery) -- is this. With this car,
> ignition OFF, the alternator's + terminal should have power, and
> indeed, the test light lights up. And, both the Field wire on
> alternator, and Field and Ignition wires on regulator all do NOT light
> up with ignition OFF, engine OFF.
>
> However -- with ignition ON, engine OFF, all FOUR of those wires light
> up! -- though, I would estimate that the + terminal of Alternator and
> the Ignition wire of the regulator are getting more volts than the
> Field wire on both Alternator and Regulator, because the light is
> brighter on the + or ignition wires.
>
> Now, someone advised me that in that last scenario, ONLY the Field
> light should be on unless the battery is discharged (granted, which
> mine probably is), but I still think there's something screwy going
> on.... My next step is going to be bypassing the harness and connecting
> wires directly between Regulator Field and Alternator Field, and
> Regulator Ignition to Battery Positive Terminal.
>
> Any tips/suggestions/name calling?
>
> Thank you,

Nothing weird going on there. Start with a new or charged battery. Your
battery is so dead it barely supports a test light and goes off when
the ignition is turned on. If you could invest in a $10 VOM you could
measure this as it happened.

Will wrote:
> Really? I know this probably sounds naive, but hey, I have no problem
> sounding naive! :-)
>
> When I tested this last night and got the results above, I had charged
> the battery, and driven maybe 20 minutes, tops. I've been finding I can
> drive at least 60 minutes on this charged battery, though admittedly
> I'm sure the battery's not in great shape from frequent
> charging/discharging.
>
> I was thinking that the instant off of the test light was more due to a
> short or missing ground somewhere... but you really think it's a dead
> battery giving that result?
>
> Thank you,
>

It would have to be one bad short and you would see the smoke and stink
to go with it.

The battery is bad.


--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

you can drive 60 minutes and then what? It quits?
your charging system is hosed for one thing.

My first guess would be a bad connection between the cable clamp and
battery post. This connection can pass enough for the test light, but
put a small load on it and it fails so the light goes out. Put a large
load on it and it can arc so the starter can turn.

It is unlikely you have a battery that flat dead if you can start it and
drive it for an hour after it 'takes' a charge. If the battery is bad
enough to show 0 for a test light, the charger shouldn't work.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Will wrote:
>
> OK, I am pretty sure it doesn't matter what specific car I have, other
> than that it is a 12 volt negative grounded vehicle, with a separate
> alternator, regulator, but I'll go ahead and say it... this is a 1971
> Citroen 2CV.
>
> Here are the two things I think are weird. The first may not be an
> issue, because I haven't tested any other cars to see if they do the
> same thing, but instinctively I think it's not right. When I put
> connect a test light from the postive to negative battery terminals,
> with the ignition OFF, the light lights up. When I turn the key, so
> ignition is ON, but the engine is not running, the test light does not
> light up. That just seems wrong to me, as if the ignition wasn't
> grounded or something. But you experts tell me.
>
> The second thing, that is more at the heart of the problem I'm having
> (charging system not charging the battery) -- is this. With this car,
> ignition OFF, the alternator's + terminal should have power, and
> indeed, the test light lights up. And, both the Field wire on
> alternator, and Field and Ignition wires on regulator all do NOT light
> up with ignition OFF, engine OFF.
>
> However -- with ignition ON, engine OFF, all FOUR of those wires light
> up! -- though, I would estimate that the + terminal of Alternator and
> the Ignition wire of the regulator are getting more volts than the
> Field wire on both Alternator and Regulator, because the light is
> brighter on the + or ignition wires.
>
> Now, someone advised me that in that last scenario, ONLY the Field
> light should be on unless the battery is discharged (granted, which
> mine probably is), but I still think there's something screwy going
> on.... My next step is going to be bypassing the harness and connecting
> wires directly between Regulator Field and Alternator Field, and
> Regulator Ignition to Battery Positive Terminal.
>
> Any tips/suggestions/name calling?
>
> Thank you,

Will > wrote:
>
>Here are the two things I think are weird. The first may not be an
>issue, because I haven't tested any other cars to see if they do the
>same thing, but instinctively I think it's not right. When I put
>connect a test light from the postive to negative battery terminals,
>with the ignition OFF, the light lights up. When I turn the key, so
>ignition is ON, but the engine is not running, the test light does not
>light up. That just seems wrong to me, as if the ignition wasn't
>grounded or something. But you experts tell me.

No, the light isn't lighting up because you are placing a heavy load
on the battery. Either the battery is almost dead and unable to light
anything other than that single test light, or you are placing something
close to a dead short across the battery.

>The second thing, that is more at the heart of the problem I'm having
>(charging system not charging the battery) -- is this. With this car,
>ignition OFF, the alternator's + terminal should have power, and
>indeed, the test light lights up. And, both the Field wire on
>alternator, and Field and Ignition wires on regulator all do NOT light
>up with ignition OFF, engine OFF.

>However -- with ignition ON, engine OFF, all FOUR of those wires light
>up! -- though, I would estimate that the + terminal of Alternator and
>the Ignition wire of the regulator are getting more volts than the
>Field wire on both Alternator and Regulator, because the light is
>brighter on the + or ignition wires.

This does not correlate well at all with the earlier assertion up there
that a light across the battery doesn't even light up when the ignition
is turned on.

But, it's reasonable enough.

>
>Now, someone advised me that in that last scenario, ONLY the Field
>light should be on unless the battery is discharged (granted, which
>mine probably is), but I still think there's something screwy going
>on.... My next step is going to be bypassing the harness and connecting
>wires directly between Regulator Field and Alternator Field, and
>Regulator Ignition to Battery Positive Terminal.
>
>Any tips/suggestions/name calling?

I'd go back and check and make absolutely sure that the lamp across
the battery isn't lighting with the thing on. And if that really is
the case, I'd try and find out why.

I'd also get a voltmeter, and measure battery voltage with the ignition off,
with the ignition on, an with the engine running. That is really your
first step.

And if the battery is good, but is being pulled down when you turn the
engine to on, I'd check the ignition switch. As I recall it's fails
in bizarre ways on the 2CV.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

I *know* the charging system is not working. I've known that for a
long time. What I'm trying to get at is the cause, because the alt is
putting out voltage, and the regulator is new (though, granted, could
be faulty), and the battery must be at least good enough to take some
charge, otherwise I wouldn't be able to turn the engine over and drive
around.

I thought not having any voltage showing up across the battery
terminals was a good indicator of a short, or rather, a missing ground
somewhere -- ignition switch was my inclination.

I started to trace each of the 4 wires from the ignition switch, but I
don't think I know how to test a ground wire -- my test light won't
light up when connected to a good ground wire, will it? What else can
I do?

Thank very much for your help,

Will > wrote:
>
>I started to trace each of the 4 wires from the ignition switch, but I
>don't think I know how to test a ground wire -- my test light won't
>light up when connected to a good ground wire, will it? What else can
>I do?

Connect one side of the test light to the positive terminal on the battery.
If you touch the other side to a good ground, the lamp will light.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Will wrote:
> I *know* the charging system is not working. I've known that for a
> long time. What I'm trying to get at is the cause, because the alt is
> putting out voltage, and the regulator is new (though, granted, could
> be faulty), and the battery must be at least good enough to take some
> charge, otherwise I wouldn't be able to turn the engine over and drive
> around.
>
> I thought not having any voltage showing up across the battery
> terminals was a good indicator of a short, or rather, a missing ground
> somewhere -- ignition switch was my inclination.
>
> I started to trace each of the 4 wires from the ignition switch, but I
> don't think I know how to test a ground wire -- my test light won't
> light up when connected to a good ground wire, will it? What else can
> I do?
>
> Thank very much for your help,
Somebody once said that if the only tool in your toolbox is a hammer,
everything looks like a nail. Think about using a tool other than that
one test light you have.

Al Bundy wrote:
>
> Will wrote:
> > I *know* the charging system is not working. I've known that for a
> > long time. What I'm trying to get at is the cause, because the alt is
> > putting out voltage, and the regulator is new (though, granted, could
> > be faulty), and the battery must be at least good enough to take some
> > charge, otherwise I wouldn't be able to turn the engine over and drive
> > around.
> >
> > I thought not having any voltage showing up across the battery
> > terminals was a good indicator of a short, or rather, a missing ground
> > somewhere -- ignition switch was my inclination.
> >
> > I started to trace each of the 4 wires from the ignition switch, but I
> > don't think I know how to test a ground wire -- my test light won't
> > light up when connected to a good ground wire, will it? What else can
> > I do?
> >
> > Thank very much for your help,
> Somebody once said that if the only tool in your toolbox is a hammer,
> everything looks like a nail. Think about using a tool other than that
> one test light you have.

That should be: If your only tool is a hammer, every problem looks like
a thumb. ;-)

But its the right idea. The test light can't tell you whether the
battery is good, but dead and the charging system is hosed, or vice
versa. Take the car to a shop with a charging system tester.

--
Paul Hovnanian
------------------------------------------------------------------
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