Alternator charge switch on 1991 Honda civic SI

[somedude88]

I want to take a moment to tell you I appreciate the help I would be lost otherwise.

Anyways I got it all hooked up, I flip my switch to the mode I have created to come on only when the brake is pressed... I start the car in neutral push clutch, I do not touch brake, car starts, Battery voltage, not charging, press brake engine gets a load, it charges. Let off brake... relay clicks to kill field with lightbult, light bulb lights dimly, but battery charging voltage does not change or budge a tenth of an inch.

I started small, with an instrument panel bulb, then a standard corner marker light, then to a license plate bulb. The last bulb does not light. I tested voltage across bulb when connected .2vdc 0vac. With the bulb out of the socket I soldered in I get 12.4volts, however battery is charging at around 14 volts on my volt meter.

I would put a higher load on it but I don't want to burn anything out as I know these alts are difficult to get out on this car and it's winter.

Any ideas? I can kill and restart engine with same pattern, coil dies until regenerated.

Let me know if I need to draw a schematic of exactly how I have it setup... it won't be pretty but I'll try if you want.

[deathtrain]

what does it do with out the lights bulb? does it still sit idle and not charge....and my question is why did you hook it up to the brake lights anyway? I think you would get more gains by EOC. if you dont EOC then cool it works. good for you. and yes post up your wiring schematic for anyone else who might need it.

[drmiller100]

dude you hooked it up like I was thinking. Now I am puzzled.

I'll go in tomorrow and test it on my car.

[brucepick]

drmiller, can you maybe post a little schematic of what you have in mind? After you test it out of course.

Talking about the black and yellow wire:
Specifically, I hope you can clarify -
Do you mean to connect that wire to ground via a bulb, without creating a break in the wire?
Or do you mean to break the wire, and ground one side via a bulb? If so, which side of the break would be grounded via a bulb?

Thanks!!

[drmiller100]

two modes.
One mode the voltage goes through the key switch and into the alternator (the way it is right now).
The other mode, break the connection to the key switch, and ground the alternator wire through the lightbulb.

[brucepick]

Aha.
So normally, that wire carries voltage from the battery to alternator via ignition switch.

However with that wire severed, voltage goes from alternator to ground via a bulb, if you provide a path.

[drmiller100]

Bruce. Exactly.

also, to be REALLY technical, in normal operation, power goes from ignition switch, into one leg of the alt light on the dash, out the other leg, then to the alternator.

this is how most all internally regulated alternators are wired.

[somedude88]

Originally Posted by deathtrain

what does it do with out the lights bulb? does it still sit idle and not charge....and my question is why did you hook it up to the brake lights anyway? I think you would get more gains by EOC. if you dont EOC then cool it works. good for you. and yes post up your wiring schematic for anyone else who might need it.

If you sit the car and idle it, battery will die.

My planned setup has two positions, normal operation, it charges, 2nd position charges only when brake pedal is pressed. Hooking it up when I hit the brakes is a purpose of regenerative breaking, if I'm stopping I don't need any power so no matter if I'm in gear or in neutral braking the power can be robbed from the engine to charge the battery and not when I'm accelerating.

Here is my schematic. It works great and functions properly, however my alternator after starting the car stays excited while engine is running even with the suggested alternator bulb ground.

http://i243.photobucket.com/albums/f...s/IMAG0241.jpg

Relay is shown in off position, this would be equivalent to non charging state.

So my circuit seems to be good I just don't know how to stop the alternator after I press the brake for the first time.

[somedude88]

Originally Posted by somedude88

If you sit the car and idle it, battery will die.

I do plan to change this but only until I can get this alternator to disable after the initial starting.

[California98Civic]

Originally Posted by drmiller100

the black yellow wire is the one we are talking about.

do NOT just ground it, ever.

if you unhook it, then start the car, the alternator will not charge.
If you then hook it up, the alternator will start charging.

If you then unhook it, with the car still running, the alternator will still charge.

You need to "ground it gently through a lightbulb" to kill the field so it quits charging.

Would a lighted switch on the dash do the job? I think it would be a bit less than 5 watts.