alternator circuit question

"Jim Thompson" > wrote in message
news
> On Fri, 19 Nov 2004 23:33:13 -0000, "exxos" > wrote:
>
>>
>>"Jim Thompson" > wrote in message
. ..
>>> On Fri, 19 Nov 2004 22:26:37 -0000, "exxos" > wrote:
>>>
>>>>
>>>>"maxpower" > wrote in message
...
>>>>>i would check out the circuit before cutting and adding resistors and
>>>>> regulators, try to keep eveything working the way it was designed,
>>>>> many
>>>>> a
>>>>> times i have found the 8 way connectors loose/corroded causing a no
>>>>> charge
>>>>> condition. just a simple back probe test to the PCM
>>>>
>>>>
>>>>assuming you replied to my msg, the lamp was part of those car
>>>>diagnostic
>>>>"features", I think the idea was that if the regulator shorted out it
>>>>would
>>>>light the lamp on the dash... only mine had a I/O short (at some point
>>>>in
>>>>its life) so the lamp never lite, but yet the battery was charging to to
>>>>19V... It also doubled up to raise the regulator voltage to about
>>>>13V....so
>>>>much for technology..... good idea in theory though ;-)
>>>>
>>>>chris
>>>>
>>>>
>>> [snip]
>>>
>>> I think you'll find that the lamp was looking at the neutral
>>> (mid-point of the "Y") terminal of the alternator, which is where most
>>> idiot lights get their information... actually quite good at
>>> indicating faults _before_ the battery goes dead.
>>
>>
>>It was in the ground, I actually grounded the point instead of going via
>>the
>>lamp, battery only got around 11V on it though at least it proved the
>>point.
>>It was actually a 12V regulator, I measued it with a DMM at the time and
>>even at high revs it only ever hit 12.5V, so it needed a higher ground
>>ref,
>>hence via the dash lamp. I would never have thought they would do such
>>tricks like that on cars, ive seen it countless times on electronics
>>equipment, though was supprised to see the same trick on a car.
>>
>>Chris
>>
>
> What brand of car? Yugo ?:-)

Citroen (SP?) did well lasted a long time, have a reno now, exloded last
week, ah off topic again....

Chris




>
> ...Jim Thompson
> --
> | James E.Thompson, P.E. | mens |
> | Analog Innovations, Inc. | et |
> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
> | Phoenix, Arizona Voice480)460-2350 | |
> | E-mail Address at Website Fax480)460-2142 | Brass Rat |
> | http://www.analog-innovations.com | 1962 |
>
> I love to cook with wine. Sometimes I even put it in the food.

On Sat, 20 Nov 2004 08:34:23 -0000, "exxos" > wrote:

>
>"Jim Thompson" > wrote in message
>news
[snip]
>>>It was actually a 12V regulator, I measued it with a DMM at the time and
>>>even at high revs it only ever hit 12.5V, so it needed a higher ground
>>>ref,
>>>hence via the dash lamp. I would never have thought they would do such
>>>tricks like that on cars, ive seen it countless times on electronics
>>>equipment, though was supprised to see the same trick on a car.
>>>
>>>Chris
>>>
>>
>> What brand of car? Yugo ?:-)
>
>Citroen (SP?) did well lasted a long time, have a reno now, exloded last
>week, ah off topic again....
>
>Chris
>

Pondering, it could be a form of temperature compensation. In a
Citroen, who knows ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Sat, 20 Nov 2004 08:34:23 -0000, "exxos" > wrote:

>
>"Jim Thompson" > wrote in message
>news
[snip]
>>>It was actually a 12V regulator, I measued it with a DMM at the time and
>>>even at high revs it only ever hit 12.5V, so it needed a higher ground
>>>ref,
>>>hence via the dash lamp. I would never have thought they would do such
>>>tricks like that on cars, ive seen it countless times on electronics
>>>equipment, though was supprised to see the same trick on a car.
>>>
>>>Chris
>>>
>>
>> What brand of car? Yugo ?:-)
>
>Citroen (SP?) did well lasted a long time, have a reno now, exloded last
>week, ah off topic again....
>
>Chris
>

Pondering, it could be a form of temperature compensation. In a
Citroen, who knows ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

On Thu, 18 Nov 2004 17:28:39 -0700, Jim Thompson
> wrote:

>On Fri, 19 Nov 2004 00:11:51 GMT, "Jon G." >
>wrote:
>
>>I have a 91 Plymouth Acclaim, and the alternator doesn't charge
>>the battery. I took the alternator out and had it tested, and
>>there's nothing wrong with it. I put a new battery in it, but
>>it still won't charge. I checked the fuseable link from the
>>alternator to the battery, and there is continuity. Therefore,
>>it must be the computer.
>>
>>there are 4 connections on the alternator
>>
>>L1: direct to battery, positive
>>L2: direct to battery, negative
>>c1: small wire, logic, to computer, activates diode
>>c2: small wire, logic, to computer, also battery ground.
>>
>>I want to activate the alternator continuously and put on an
>>external voltage regulator.
>>
>>What must the voltage (and current), to the logic inputs c1 & c2
>>be to do so?
>>
>>I have in mind to run a potentiometer between L1 and c1, and
>>adjust it until the alternator kicks on.
>>
>>The schematic shows that c1 goes to the coil of a transformer in
>>the alternator, which then goes to one of the diodes (an SCR?)
>
>Check your car wiring diagram and locate the regulator.
>
> ...Jim Thompson

The engine control computer has the regulator built in, and an
external regulator CAN be installed.

On Thu, 18 Nov 2004 17:28:39 -0700, Jim Thompson
> wrote:

>On Fri, 19 Nov 2004 00:11:51 GMT, "Jon G." >
>wrote:
>
>>I have a 91 Plymouth Acclaim, and the alternator doesn't charge
>>the battery. I took the alternator out and had it tested, and
>>there's nothing wrong with it. I put a new battery in it, but
>>it still won't charge. I checked the fuseable link from the
>>alternator to the battery, and there is continuity. Therefore,
>>it must be the computer.
>>
>>there are 4 connections on the alternator
>>
>>L1: direct to battery, positive
>>L2: direct to battery, negative
>>c1: small wire, logic, to computer, activates diode
>>c2: small wire, logic, to computer, also battery ground.
>>
>>I want to activate the alternator continuously and put on an
>>external voltage regulator.
>>
>>What must the voltage (and current), to the logic inputs c1 & c2
>>be to do so?
>>
>>I have in mind to run a potentiometer between L1 and c1, and
>>adjust it until the alternator kicks on.
>>
>>The schematic shows that c1 goes to the coil of a transformer in
>>the alternator, which then goes to one of the diodes (an SCR?)
>
>Check your car wiring diagram and locate the regulator.
>
> ...Jim Thompson

The engine control computer has the regulator built in, and an
external regulator CAN be installed.

Hi D.S.,

We rigged it up like you said, and the thing works! I got a
voltage regulator at Advance Auto from off your list, wired
everything, and now there's 14 volts of charge on the battery.

Thank you for your help. It saved me from having to get another
computer.

Regards,

Jon

Daniel J. Stern wrote:
> On Fri, 19 Nov 2004, exxos wrote:
>
>
>>I had a problem with one of my cars in the past with the alternator not
>>charging, what this turned out to be was the ground pin on the regulator
>>was going via a lamp on the dashboard, thus giveing a slight volt raise
>>on the ground so you got maybe 13V from the 12V regulator, though it
>>took me a long time to work out why my battery wouldn't charge, turns
>>out the bulb went on the dashboard, no ground on the regulator,
>>alternator didn't charge the battery, thus car wouldn't start....
>
>
> Fun story, but not applicable to the original poster's '91 Acclaim -- not
> even a little bit. Also, "12v" automotive voltage regulators have set
> points of between 13.8 and 15.1 volts. A regulator with a set point of 12v
> would not charge the battery.

Hi D.S.,

We rigged it up like you said, and the thing works! I got a
voltage regulator at Advance Auto from off your list, wired
everything, and now there's 14 volts of charge on the battery.

Thank you for your help. It saved me from having to get another
computer.

Regards,

Jon

Daniel J. Stern wrote:
> On Fri, 19 Nov 2004, exxos wrote:
>
>
>>I had a problem with one of my cars in the past with the alternator not
>>charging, what this turned out to be was the ground pin on the regulator
>>was going via a lamp on the dashboard, thus giveing a slight volt raise
>>on the ground so you got maybe 13V from the 12V regulator, though it
>>took me a long time to work out why my battery wouldn't charge, turns
>>out the bulb went on the dashboard, no ground on the regulator,
>>alternator didn't charge the battery, thus car wouldn't start....
>
>
> Fun story, but not applicable to the original poster's '91 Acclaim -- not
> even a little bit. Also, "12v" automotive voltage regulators have set
> points of between 13.8 and 15.1 volts. A regulator with a set point of 12v
> would not charge the battery.

On Sun, 21 Nov 2004, Jon G. wrote:

> Hi D.S.,
>
> We rigged it up like you said, and the thing works!

Once again the forces of goodness and light triumph over the forces of
rottenness and dark.

> I got a voltage regulator at Advance Auto from off your list

Which one did you wind up getting?

> wired everything, and now there's 14 volts of charge on the battery.

Did you have to put a resistor across the original field wires to keep the
Check Engine light from coming on?

> Thank you for your help. It saved me from having to get another
> computer.

N/P, glad to help.

DS (Those who said this wouldn't work: Neener-neener-neener.)

On Sun, 21 Nov 2004, Jon G. wrote:

> Hi D.S.,
>
> We rigged it up like you said, and the thing works!

Once again the forces of goodness and light triumph over the forces of
rottenness and dark.

> I got a voltage regulator at Advance Auto from off your list

Which one did you wind up getting?

> wired everything, and now there's 14 volts of charge on the battery.

Did you have to put a resistor across the original field wires to keep the
Check Engine light from coming on?

> Thank you for your help. It saved me from having to get another
> computer.

N/P, glad to help.

DS (Those who said this wouldn't work: Neener-neener-neener.)

This idea of installing an external voltage regulator to bypass
a faulty computer, doesn't work. I put one on and it charged at
14 volts for about a day, then it jumped to 18 volts. I tried a
different brand voltage regulator, and it did the same. The
battery is boiling and smells like sulfur, the high beams went
out, and I'm in the hole for 2 voltage regulators that work like
junk.

I have a 7 watt 1.2 ohm ceramic resistor out of a TV set. It
can only handle 2 amps. If I put it in series between the
regulator and the alternator field, it should drop the voltage
to the field by 3 volts. However, I think I need a heavier duty
resistor.

Jon

Jon G. wrote:

> I have a 91 Plymouth Acclaim, and the alternator doesn't charge the
> battery. I took the alternator out and had it tested, and there's
> nothing wrong with it. I put a new battery in it, but it still won't
> charge. I checked the fuseable link from the alternator to the battery,
> and there is continuity. Therefore, it must be the computer.
>
> there are 4 connections on the alternator
>
> L1: direct to battery, positive
> L2: direct to battery, negative
> c1: small wire, logic, to computer, activates diode
> c2: small wire, logic, to computer, also battery ground.
>
> I want to activate the alternator continuously and put on an external
> voltage regulator.
>
> What must the voltage (and current), to the logic inputs c1 & c2 be to
> do so?
>
> I have in mind to run a potentiometer between L1 and c1, and adjust it
> until the alternator kicks on.
>
> The schematic shows that c1 goes to the coil of a transformer in the
> alternator, which then goes to one of the diodes (an SCR?)