alternator/injector battery offset?
 

Ok I am trying to tune injector battery off set a little better. So I did a few things. First I turned off the eld this seamed to not change voltage a lot. Then I installed 2 on off switches next to the ecu in the alternator control wire and the alternator rf wire this did not change voltage a lot (red dots). So I just unplugged the alternator this changed voltage a lot.

My question is what dose the eld, alternator control wire and rf wire do anyway? Dug threw books searched on line even asked a master honda tech (LOL) not a lot of clear answers. All I do know is the eld is in the fuse box and it looks like its and inductive amp meter/sensor book just said its used to control the alternator. Can some one clear this up I was looking for a way to tune injector battery offset with out disconnecting the alternator engine running and wandering wtf all this ---- if for.

This is for my car.
Attachment 10459

Re: alternator/injector battery offset?
 

Heard something about the ecu will shut off the alternator at full throttle to help build hp? Is this bogus? So maybe on off switches are not a good idea. Maybe the ecu sends voltage during full throttle so confused.


Any one?

Re: alternator/injector battery offset?
 

I've never heard of the alternator shutting off during full throttle. If you'd like to test that theory then unplug your battery after you start your car then go for a run. It may run like ass but I'd bet that it doesn't shut down if your alternator is worth a ----.

Re: alternator/injector battery offset?
 

Alternator always spins with the belt and it's not like AC pump which has an on/off pulley. Alternator will always spins and take hp away, unless the electric current/power that it builds up helps the motor run. (stronger spark, more fuel pressure when needed and more ----.)

Re: alternator/injector battery offset?
 

the more current you draw through an alt. the more load it puts on an engine. You can't physically turn off an alt. like an a/c pump but you can remove the load against it and thus the load it adds to the engine.

Not that it has anything to do with the thread just correcting your useless misinformation.

Re: alternator/injector battery offset?
 

Honda tech came threw I guess because I stumped him he gave me this. So I just have to find out if the alt signal wire is 5v or 12v and I should be able to turn off the alternator from inside the car with out extending the power wire for the voltage regulator . Now we all know.
Attachment 10434
Attachment 10435

Re: alternator/injector battery offset?
 

You are misunderstanding what an ELD is for. It is an electronic LOAD detector, the concept behind this is that under high electrical load demand the alternator is harder to turn, which LOADs the engine. The ECU uses this information to idle the engine up slightly. Since over half the Hondas on the planet didn't come equipped with one you can surmise it's pretty useless.

Alt FR is a signal sent from the voltage regulator to the ECU, it is the alternator telling the ECU how loaded it thinks it is. ~4.5 volts at idle with the electrical system unloaded, and it decreases as you turn the headlights and blower motor, etc, on.

Alt C I can't find any information about, but it's run to transistor Q37. The alternator throws a voltage out on it (I ASSume 5Vref) and the ECU starts dropping part or all of that to ground by either moving the Q-point of the transistor around, or simply turning the transistor all the way "on," saturating it, and causing it to ground the C signal.

If you really want to ---- around put a 10K potentiometer between the Alt C signal coming from the alternator + ground, and slooowly start lowering the resistance between the alternator and ground... if it works, let us know, If you ---- something up, let us know. Good luck. :P

Re: alternator/injector battery offset?
 

Well, looky what you found. :P

Re: alternator/injector battery offset?
 

Found one more thing.
Attachment 10295
SO I tried a 10K potentiometer in the alternator control did not change anything. Do you think the alternator control is an output from the ecu or and input?

Should I try to some how send a 5v signal to the alternator. If this works I will try to adapt this into my obd1 to obd1 harness I use to capture data for logworks 3 and I will have an easy way to turn off any cars alternator.


I seems to me that the system works like this

The eld just senses amperage if it is under 10 amps, vehicle speed is below 40, rpms below 3600, ect above 140, ac off and iat above 65. The ecu uses the alternator control wire to send a signal to the alternator to reduce the voltage regulators goal. The rf signal is just an input to the ecu to tell it to bump up the idle under high electrical demand.

One other dumb question in injector battery offset it list a value of voltage. Is one of the hot wires going into the ecu monitored?

Re: alternator/injector battery offset?
 

Ok hold on I see what you are saying now davis. So it is and output from the ecu but the ecu grounds the alternator control wire to control the alternator.

Ok let me set this up different and get back. I just had it between the alt control and the ecu.