Civic alternator shut off, the easy way

[cbaber]

Check out this thread: http://ecomodder.com/forum/showthrea...8-a-20513.html

This probably has something to do with why your alternator is not completely shutting off. Here is the important part:

1 - You must disable two of the wires to the 4P connector, not just one: the sixth gen Civic's "smart alternator" has a four wire connector (a "4P" connector) and a separate large gauge white power wire for the alternator's power output to the battery. On the connector, one wire is for the charging light signal (blu/wht), another is the power line (blk/yel) for the field windings, and the two others are signal and control wires to and from the ECU. If you cut only the power line (blk/yel) the alt will still power using the blu/wht charging lamp wire. I know this because I tested for it using short wires with male and female spade connectors. I interrupted one line at a time and then two at a time until I was able to shut the alt off. You must interrupt both the blu/wht and blk/yel lines. A similar discovery was made by "busypaws" for his 1997 Protege DX alternator switch (he resolved the problem differently).

[steffen707]

Originally Posted by cbaber

Check out this thread: http://ecomodder.com/forum/showthrea...8-a-20513.html

This probably has something to do with why your alternator is not completely shutting off. Here is the important part:

Thanks for the link, that's also a good read, but I was hoping that the grounding method would provide a more simple way to achieve alternator shut off than having to disable 2 wires, also i've heard from some ecomodders that have done the 2 wire shutoff as described in your link and that didn't work either.

We don't know for sure yet if the grounding of the alternator control wire still charges but at a lower 12.5volt rate, or if its actually working.

Any good ideas to test the alternator output to verify if it is still charging but at a lower rate? Would that light bulb between the alternator and battery ground work like I suggested trying?

[California98Civic]

Good luck with the further tests! Please report more on your findings. Nothing cooler than testing something and being willing to admit if the test has failed, if it has failed.

And I like the FE results you are suggesting (which confirm my similarly sketchy results). It would be nice to know if the alt really was off.

One observation: your design is simpler than the one I posted, and that cbaber linked above. But the only extra thing I did was unplug the charging light wire near the driver's side firewall grommet, right? That's reversible in 30 seconds.

Originally Posted by steffen707

Thanks for the link, that's also a good read, but I was hoping that the grounding method would provide a more simple way to achieve alternator shut off than having to disable 2 wires, also i've heard from some ecomodders that have done the 2 wire shutoff as described in your link and that didn't work either.

I know brucepick has had difficulty with the method I describe in the linked post, but he is not sure yet what the source of the failure is. I haven't seen any others mentioning problems. Who are you referring to?

I have a voltmeter on my dash, and for what it's worth to anyone: in 7 months my alternator has not once begun charging unless I turned it on. If I drain the battery below 12.5 volts or if electrical load brings the voltage down below 12.5, it stays there, the alt does not turn on unless I flip the dash-mounted switch. Quite handy, really.

Thanks again,
james

[WD40]

Europe and Canada do not have ELD.
I have 14.2 ish volt on battery on idle all the time.
So I gather I cant lower mine to 12.5, that sucks.

[steffen707]

Originally Posted by California98Civic

Good luck with the further tests! Please report more on your findings. Nothing cooler than testing something and being willing to admit if the test has failed, if it has failed.

And I like the FE results you are suggesting (which confirm my similarly sketchy results). It would be nice to know if the alt really was off.

One observation: your design is simpler than the one I posted, and that cbaber linked above. But the only extra thing I did was unplug the charging light wire near the driver's side firewall grommet, right? That's reversible in 30 seconds.



I know brucepick has had difficulty with the method I describe in the linked post, but he is not sure yet what the source of the failure is. I haven't seen any others mentioning problems. Who are you referring to?

I have a voltmeter on my dash, and for what it's worth to anyone: in 7 months my alternator has not once begun charging unless I turned it on. If I drain the battery below 12.5 volts or if electrical load brings the voltage down below 12.5, it stays there, the alt does not turn on unless I flip the dash-mounted switch. Quite handy, really.

Thanks again,
james

I was also referring to brucepick's problems.

When you said that it won't drop below 12.5 volts, do you mean that you physically don't let it drop below 12.5 volts because you use your dash mounted switch to turn it back on?

Or are you saying that with your kill switch the alternator is always off and just doesn't fall below 12.5volts? Because if the later is the case, it would make me think that the alternator is stuck in this 12.5 volt "low setting" that Gasoline Fumes says mine might be in.

[California98Civic]

Originally Posted by steffen707

When you said that it won't drop below 12.5 volts, do you mean that you physically don't let it drop below 12.5 volts because you use your dash mounted switch to turn it back on?

Or are you saying that with your kill switch the alternator is always off and just doesn't fall below 12.5volts? Because if the later is the case, it would make me think that the alternator is stuck in this 12.5 volt "low setting" that Gasoline Fumes says mine might be in.

Neither. An example: today doing P&G with EOC on my way to work, in the cold, with the alternator off, the voltage would get down to 12.3 during the pulse phase and stay thereabouts for the whole pulse length, whether 5 seconds or an entire minute. Then during the EOC glide phase, with decreased load from the ignition system, the voltage would return to 12.6 or 12.7, which is near full charge. With my previous battery, which did not have as much capacity, I would drive for miles without seeing the voltage return to 12.5, whether the engine was off or on. But it is true that this design will not accomplish your desire to be able to cut the alt off and have it shut down, without cutting the engine for at least a second, as I do with my injector cut-off. I think drmiller's idea of a small light bulb on the line to drain residual voltage might be another way to accomplish your goal. I just didn't need it because my car is off so much of the time, so often, while I drive.

I have not had the alternator on for days now. It's all grid charging.

[steffen707]

I just loaded a bunch of pictures to post 2 of the thread.

[brucepick]

I think the alternator's reduced-charging mode is actually a not-charging mode.

A lead acid battery has a "resting" voltage of 12.5V. It will usually settle there if there's no load, or a very low load, like just the computer + maybe the radio running. With alt not charging, it will then gradually drop over a minute or two. A deep cycle battery drops much more slowly. Once the battery voltage has dropped to whatever the ELD circuit's low voltage limit is, the ELD reactivates the alternator to charge the battery.

So I suspect the ELD circuit cuts the alt's output, and the car "coasts" on the existing charge in the battery. In normal use (not with an alt delete mod done to the car) the ELD only cuts the alt output intermittently, so in between those outages the battery is getting topped up.

Non-charging mode is only available if these conditions are met (I tested and watched carefully):
Speed below 50 mph
Headlights off
Battery topped up
Heavy consumption accessories not running (example, fan on speed one is OK, but not speed 3-4)
Car NOT coasting in gear (ELD is programmed to take advantage of the "free" energy of the coast, and will use it to charge the battery)


So in normal driving, it will cycle in and out of not-charging mode as conditions change. Battery is slightly depleted after startup, and the alt charges normally till it's topped up. The ELD circuit can sense the current "drain" presented to the alt by the slightly depleted battery that powered the computer + clock all night, and then started the car.

When hypermiling, with EOC and DFCO and whatever other methods, not-charging mode will also cycle on and off based on the same requirements.

[steffen707]

Originally Posted by brucepick

I think the alternator's reduced-charging mode is actually a not-charging mode.

A lead acid battery has a "resting" voltage of 12.5V. It will usually settle there if there's no load, or a very low load, like just the computer + maybe the radio running. With alt not charging, it will then gradually drop over a minute or two. A deep cycle battery drops much more slowly. Once the battery voltage has dropped to whatever the ELD circuit's low voltage limit is, the ELD reactivates the alternator to charge the battery.

So I suspect the ELD circuit cuts the alt's output, and the car "coasts" on the existing charge in the battery. In normal use (not with an alt delete mod done to the car) the ELD only cuts the alt output intermittently, so in between those outages the battery is getting topped up.

Non-charging mode is only available if these conditions are met (I tested and watched carefully):
Speed below 50 mph
Headlights off
Battery topped up
Heavy consumption accessories not running (example, fan on speed one is OK, but not speed 3-4)
Car NOT coasting in gear (ELD is programmed to take advantage of the "free" energy of the coast, and will use it to charge the battery)


So in normal driving, it will cycle in and out of not-charging mode as conditions change. Battery is slightly depleted after startup, and the alt charges normally till it's topped up. The ELD circuit can sense the current "drain" presented to the alt by the slightly depleted battery that powered the computer + clock all night, and then started the car.

When hypermiling, with EOC and DFCO and whatever other methods, not-charging mode will also cycle on and off based on the same requirements.

So you're saying that by grounding the alternator charging control wire (like the ecu does when it wants to go into "low or no charging mode") that its actually NOT charging?

If I read correctly the ELD tells the ecu what's going on and the ecu controls the alternator by just the alternator charging control wire. So the ELD isn't connected to the alternator directly.

When you just ground the alternator charging control wire, the alternator shouldn't have any idea what the ELD is.

[California98Civic]

Originally Posted by brucepick

I think the alternator's reduced-charging mode is actually a not-charging mode.

A lead acid battery has a "resting" voltage of 12.5V. It will usually settle there if there's no load, or a very low load, like just the computer + maybe the radio running. With alt not charging, it will then gradually drop over a minute or two. A deep cycle battery drops much more slowly. Once the battery voltage has dropped to whatever the ELD circuit's low voltage limit is, the ELD reactivates the alternator to charge the battery.

So I suspect the ELD circuit cuts the alt's output, and the car "coasts" on the existing charge in the battery. In normal use (not with an alt delete mod done to the car) the ELD only cuts the alt output intermittently, so in between those outages the battery is getting topped up.

One complication for this picture is that I observed 12.5 volts charging on my old battery--the dieing one--under certain conditions. In other words the battery was sitting at say 12.2 volts and I turn the alt on and the voltage goes to 12.5 or thereabouts.