Alt kill switch planning (help)

[California98Civic]

Originally Posted by deathtrain

yes that sounds correct but what does it do when you plug everything in and remove that 7.5a fuse No. 15?

I did that once. There are several components effected by that fuse, not just the alternator. That's not a solution. I have it wired now and working but I'm not sure I like it.

I unplugged the charging system light at a connector close to the fire wall. But the yel/blk wire could not be disconnected anywhere other than at the 4P connector plugged into the alt itself. Disconnection anywhere further up the line toward the fuse box also effected other systems. I cut into the line at the 4P, and put my switch onto that line.

I went for a test drive.

The alt can be powered up with a flick of the switch. Once I had turned it on, if I turned it off again it did not power down immediately. When I shut down and bump started the engine the alt would be off. So it works for EOC.

Question: the two wires linking the alt to the ECU are of course still plugged-in and what effect might they have. The ECU should be sending commands to the alt to fire up, but the alt can't, and the signal back to the ECU will therefore report nothing back the ECU instead of a signal about increased power generation. What side effects can such a scenario have?

I do a 150 mile drive tomorrow to meet up with a friend and his Geo Metro and head to a junkyard. So, if I don't have to leave my car at the junkyard, the drive should be an opportunity to test the alt kill switch more completely.

[brucepick]

Originally Posted by deathtrain

yes that sounds correct but what does it do when you plug everything in and remove that 7.5a fuse No. 15?

Tried this. Several things happen, not all of them good.
1) Alternator does not charge (that's what we wanted)
2) Check Engine Light with 2 codes. Sorry, codes not recorded.
3) Speedometer is disabled as the fuse powers it.
4) Fast idle and a rich mixture (reported by ScanGauge custom LBN gauge setup). That was on a fully warmed up engine.

[brucepick]

Originally Posted by California98Civic

... Once I had turned it on, if I turned it off again it did not power down immediately. When I shut down and bump started the engine the alt would be off...

If you do as above - turn off the alt via switch(es) after it was running - and wait for some seconds, does it stop charging?? Or does it only stop charging if you kill the engine?

Originally Posted by California98Civic

... Do I really need four switches? Is there a switch I could use that could cut all four at once?

james

James,

Based on your recent posts indicating you probably only need to cut two wires, you can do that with a DPST switch. Double Pole, Single Throw. It controls two wires with one flip lever or button. Wikipedia article section on switch types

If you needed to do the same for 3 or maybe even four wires, there are triple pole single throw TPST and probably even QPST switches (quad).

I'm very eager to find out the results of your planned additional testing tomorrow. Keep that battery charged up! I hope to do some testing in the driveway tomorrow too, but I have at least one project for my good wife. Probably more than one...

At the junkyard, try get a spare alt connector. I think the Accords use the same one, but it's right up front on the driver's side where you can get it very easily. Then you can splice your wires to it and plug it into your alt. Switches can go in between.

[California98Civic]

Results of my test run with my new alt delete switch today are to my like. I was able to drive 135 miles today mostly on the grid charge. The run to the junkyard in Riverside was in the 40s/50s AM temps, uphill, and into a significant headwind for 65 or so miles: 54mpg and I only needed to use the alternator a couple minutes to keep the battery voltage over 12volts. This was almost without EOC, almost entirely engine on coasting (G.L.E.N.). I recharged on the grid at my buddy's place while we scrounged for parts for his Metro and my Civic. Came home without ever flipping the switch to start the alt: 73.5 mpg in the 70 degree tailwind, downhill return run. My total day-long average was about 63 mpg, averaging 55-60 mph.

My main goal with the alt switch was to make it easy to return the car to alternator functions during longer trips, during which the battery could not be expected to last. I got that. Today, I could play the radio or whatever and not worry about voltage drop. My alt is merely backup now!

Brucepick: I noticed you said that your car seemed to run an A/F ratio more rich when you went alt free, correct? I don't think I encountered that. Though longterm fuel trim was somewhat rich, 0.78 going out and 1.56 coming back, I am not sure that would be very unusual in my (admittedly spotty) observation of fuel trim data on my UG.

Great drive today!

[brucepick]

Originally Posted by California98Civic

...
Brucepick: I noticed you said that your car seemed to run an A/F ratio more rich when you went alt free, correct? I don't think I encountered that. Though longterm fuel trim was somewhat rich, 0.78 going out and 1.56 coming back, I am not sure that would be very unusual in my (admittedly spotty) observation of fuel trim data on my UG.

Great drive today!

Wow - great drive, indeed!

As for my car's very rich mixture, this was in a test with the #15 fuse pulled to kill the alt. This was not the same as how you disabled your alt. And I could see that the computer was very unhappy with the missing fuse; it gave a check engine light after just a second or so, with 2 fault codes and a fast idle in addition to the rich mixture. Of course my computer would be different from yours, with the HX having lean burn capability.

Alt restart from switch ?
You wrote that on the way up you ran the alt for a couple minutes. Were you able to start the alt while the engine was running?? Or did you have to kill the engine to get the alt restarted when you restarted the engine?

Bruce

[brucepick]

Did some experimenting myself today, on my very similar '97 HX.
I decided not to cut wires, but to get a second alt connector and splice my own scheme in between that one and the original one.

My car has a belly pan so getting at the alt from below is very cramped, working through the oil change access port.

Working from above, I finally got the 4 pin connector off the alt and stripped back some of the protective covering over the 4 wires. To get some flexibility and access to the individual wires.

I kept looking at it and finally decided I didn't have enough working room to be able to splice on my own wires after cutting the existing ones about 1 inch back from the connector.

Thus, I'm back to a plan I suggested earlier. Here goes.

Get a junkyard to sell me a connector from a matching car. It's female, and goes onto the alternator. When I'm done attaching what I want to the four pigtails on the junkyard connector, it will go on to my alternator.

The connector has four wires. Two of them will be restored to their regular path: I'll crimp 1/8" male spade connectors onto those two wires on the junkyard connector. The spades will go onto my existing connector, in their matching locations; two connections restored. The other two wires on the junkyard connector will get long leads that go to a dash switch and then back to the engine bay. There they will get the same 1/8" male spades, then will be reconnected to the original alt connector that's part of my car's harness. When the dash switch is closed ("on"), the connections are restored as original. Switch off, the two wires are effectively cut.

I can push the spades into the alt harness connector; that's doable. What I can't do is cut those 4 wires on the original connector and then solder or crimp my extensions to the cut ends. No working room down there.

Unfortunately I didn't think to start the car with the connector pulled. I closed it up in a bit of a hurry to do some errands with my wife. Tomorrow I'll see about pulling off the alt connector again, to verify that it will disable the alt and not give a check engine light. But I suspect that will work fine, as long as I can get it pulled off.

[oil pan 4]

Cutting the power going between the exciter and the field winding is the safest way to cut power output from the big brushless alternators I work on. All the big generators have a small generator built in that powers the main field windings, thats the exciter.

Car alternators use external power, brushes and communtator to excite their field windings, its more compact and cheaper this way.
Its also easy to sever this type of field winding connection.

[California98Civic]

Originally Posted by brucepick

Wow - great drive, indeed!

Thanks.

Originally Posted by brucepick

Were you able to start the alt while the engine was running??

Yes. But if I shut it down again the voltage meter would continue to read 14+ volts. But if I had turned the alt back off, killed the injectors, and then bump started, the voltage would be back down to 12.6 or 12.2 or whatever.

Originally Posted by brucepick

Get a junkyard to sell me a connector from a matching car. It's female, and goes onto the alternator. When I'm done attaching what I want to the four pigtails on the junkyard connector, it will go on to my alternator.

That's clever. I was able to do my splicing from above, but it was very awkward (and I have long thing hands and fingers).

Originally Posted by brucepick

Tomorrow I'll see about pulling off the alt connector again, to verify that it will disable the alt and not give a check engine light. But I suspect that will work fine, as long as I can get it pulled off.

That's how I have been disabling my alt these last 5 months. No CEL ever. It will work perfectly. Whenever you need the alt again, you'll just need to plug it back in. That's fun when the engine is hot! But it will work. I was at a bone yard today. The only sixth gen civic was picked completely clean. If I go to another before you get your connector, I'll see about grabbing one for ya! Snip snip... in the mail!

Originally Posted by oil pan 4

Cutting the power going between the exciter and the field winding is the safest way to cut power output from the big brushless alternators I work on. All the big generators have a small generator built in that powers the main field windings, thats the exciter.

Car alternators use external power, brushes and communtator to excite their field windings, its more compact and cheaper this way.
Its also easy to sever this type of field winding connection.

This would mean getting inside the alternator?

[brucepick]

In my humble opinion, we have a new fuel saving technique. I nominate we call it Grid Powered Electrical System, or GPES. Has a bit of a ring to it. Should be in our glossary.

GPES would include:
Switchable alternator disconnect and restart
- - (Looks like the disconnect requires engine kill, but so be it)
Deep cycle battery
A/C recharge capability
- - (Configured for user convenience due to frequent use)

So far as I know, MetroMPG was the first to implement this on a petroleum powered vehicle. Of course every full EV has GPES but they are in their own league. "Alternator delete" already well enough known, but with a deep cycle battery pack and an efficient method of recharging it, you have a combination that can deliver a consistent mpg increase.

[California98Civic]

Originally Posted by brucepick

In my humble opinion, we have a new fuel saving technique. I nominate we call it Grid Powered Electrical System, or GPES. Has a bit of a ring to it. Should be in our glossary.

GPES would include:
Switchable alternator disconnect and restart
- - (Looks like the disconnect requires engine kill, but so be it)
Deep cycle battery
A/C recharge capability
- - (Configured for user convenience due to frequent use)

So far as I know, MetroMPG was the first to implement this on a petroleum powered vehicle. Of course every full EV has GPES but they are in their own league. "Alternator delete" already well enough known, but with a deep cycle battery pack and an efficient method of recharging it, you have a combination that can deliver a consistent mpg increase.

"GPES", I like it. It effectively makes a simple ICE into a crude and practical hybrid, you know? I hardly ever charge my charging system with anything other than the grid. The power I used for the 65 mile trip home yesterday came entirely from the solar panels my friend has on his house roof. Much greener than burning gasoline.

One optional addition to the "GPES" mod would be electrical load reductions (LED, HID, and such...). With load reductions I have driven my commuting distances in the cold dark without using the alternator at all. Your plans are even more promising for night driving because of the bigger deep cycle batteries you are considering.

james