I am an electrical engineer from India and I have 2010 honda city 1.5L iVtec. I was facing the same problem of voltage of alternator. Now it' ok. I suggest all to never bypass the ELD. Please connect the all heavy loads like high amp sound system or extra powerfull lights or existing headlights with high power lamps after the ELD. As shown in the photograph connect all the loads at terminal 2 after ELD. This ELD is a simple current Transformer . When any connected load draws high hmper current ELD gives current signal to ECU and ECU allows the alternator to start work at full capacity. That' all . So please connect your instruments always through ELD and never bypass the ELD.
Thanks to all
Bakhtawar Singh Matharu

 

connect your audio system though ELD. Do not connect it directly to the battery or through relay to battery. ELD will send signal current to the alternator when your audio system will draw high current and the alternator will start charging at output of 14.6 V automatically so please never bypass the ELD. It is fuel saving device.

 

Thanks for the advice but the connection in the fuse panel will not work in my case, nor would I ever tap the fuse box for such a high current load. I am installing 2 runs of 1/0 gauge power cable between the stock battery and the auxiliary AGM that will be installed in the trunk. I am also doing the Big 3 upgrade under the hood. My concern, as with others on this thread, is the voltage drop while the alternator is free wheeling. The small drop in fuel economy is of no concern to me.

 

Thank you for chiming in but as an EE you should be well aware that the 50A fuse on the ELD is sized for the loads the engineers placed on that fuse and not additional loads. Additional loads an existing fuses can overload both the fuse and the wiring (with the wiring and connections being the primary cause for concern given that fuses can handle several times their rating for a short duration). An audio signal consists of peaks and valleys which a fuse can let pass but wiring and connections will see the average power dissipated exceed their design and ratings - which is when melting or fires occurs.



Your suggestion is a safety hazard and can damage the factory wiring and fuse box. I've seen melted fuse boxes from loads being added and it's devastating. Another concern with adding loads to the ELD terminals is that the connection itself will not be ideal and will have resistance and will dissipate power (i.e. heat). Additionally, it requires you compromise the water-resistance of the fuse box itself which will let dust and moisture into the fuse box (since you have to make a wire pass-through into the cover or box).



The ELD bypass will result in a reduction in fuel economy, as previously stated, but it poses no harm to the vehicle or vehicle wiring. For those wanting a high-power sound system, a loss in fuel economy is expected as the alternator load is increased anyway.



High-current loads that are added to a vehicle should ALWAYS be added directly to the battery and NEVER to the fuse box(es). Control of these add-on devices (other than amplifiers with internal relays) is achieved through an external relay (4-pin or 5-pin). The relay coil power source can be vehicle ignition since the relay coil current is very small (tens of milliamps) and in these cases a fuse tap can be a safe application.

 

Thanks for following. I think the 9th and 10th gen bypass will be very similar to the original bypass design because it appears nothing has really changed. I cannot speak to the necessary resistor size yet as I haven't characterized the voltage drop seen by these newer vehicles.



I will still have the bypass be select-able through a relay so that fuel economy can be maintained when the sound system is low or off and current demand is low. I drive about 30k mi. per year and much of it for work with other people in the car and the sound system may be off for hours at a time - i want maximum fuel economy in those situations.



I should also be able to characterize the average drop in highway fuel economy with the bypass enabled since i make repetitive 2-hour drives.

 

I will do the original bypass you have shared with us. If I have any issues or any strange occurrences with electrical systems, I will come back and post about it.
Thanks again for your generosity and time KHA.

 

You will want to snag an accurate schematic for your vehicle so you know what wires to intercept (colors have changed). I used techinfo.honda.com for wiring schematics for my 2014.

 

I am a long-time lover of Honda for many, many years. I've had a 1980 Accord, 1987 Civic, 1996 Accord EX, and my current car, a 2006 Accord EXL NAV (which I love).
I have recently inherited a 1999 Accord EX from my mom. Mom didn't pass away. She is 96 years old and doing fine (God bless her). It has been sitting in her garage for 4 years since she quit driving at 92. The past few years, I would give it some exercise by taking her out with it once in a while. It is in mint condition with only 57000 miles on it. She bought it in 2001 with 32000 miles then. It is one of those rare finds that you have an opportunity to get a car from a little old lady that only drove it to church (it literally is almost that).

Anyway, while driving at night, I have been experiencing the sames issues with the headlights doing the dimming thing. It seems to happen when I put my turn signal on or hit the brakes. I thought I blinked my eyes or something since it happens so fast (few hundred milliseconds). It is very annoying. I'm pretty sure my 1996 Accord was doing the same thing before I let it go to a new home. I thought that the alternator was on its way out and did not want to change it since I knew it was going to be leaving soon with the new kid (2006 EXL) on the block.

I am going to do your bypass circuit, but with a little twist. I will activate the relay only when the headlights are turned on. After all, that is the time when I need to make sure the alternator stays on the higher output all the time (Right?). That is the only time I notice (and aggravates me). From what I have read here, sounds like the alternator should be in the higher output mode when the headlights are on. I have never measured the voltage during these little blips that happen. I thought that I would need a scope to measure it since it occurs so fast. I think I will wire the relay on the parking or running lights circuit, since the dash lights are affected with the dimming thing too.

The innards of the ELD seem like it should be a mystery the way it is packaged and enclosed in epoxy. What it really is, is a coil and a small circuit board with a few small surface-mount components. The metal bar that goes through the middle of the coil carries all of the current the ELD is monitoring. This current creates a magnetic field which is induced to the coil surrounding it. This causes a voltage drop to be developed across the coil (similar basis of wireless charging). The higher the current, the bigger voltage across the coil. This voltage is fed to an OP amp which processes and amplifies the signal before it comes out of the ELD and fed to the PCM. The ELD needs the 12 volt input to it so that it can power the circuitry inside.
Figured I would put a little knowledge out there about it. I have seen some different types of current monitors. I repair welding equipment and robot welders as my employment. One of the 500 amp monitoring boxes I repair has one of these devices with a big shunt bar going through it. The circuit is designed and calibrated to produce 1 volt for every 100 amps of current flowing.

I will do this mod in the next week or two (definitely before cold weather hits) and give an update to how everything turned out. I am using this as my main car at the moment, until I get a tranny leak in the 06 Accord under control (that is for another thread).

One last thing........<<< Keep Hope Alive>>>........ Would the capacitor bank along with a standard battery (700 cca) be good or help in this situation? Or is it that the ELD has gone kaput ? (bad OP amp probably to blame)

 

This little problem child has proven to provide a lot of people with voltage issues, especially when adding additional electronics to the system. I was kicking around the idea of just adding another ELD to the main power wire of either the battery, or lead to amps, and then pair all of the connections from the ELD to the current one in the fuse box, would it not just detect the new load as though it was part of the original load?

I haven't tried this yet, however, I'm not able to see what would be wrong with an additional ELD in parallel to the original one, discovering new loads.

 

You'd have to be very careful with the load that the ECM sees or you'd damage it. Shunt resistors in parallel would also lower the load seen so maybe adding a resistor in series before the parallel combination would be suitable.

If you undertake this, feel free to share. The shunt resistor would be pretty big to handle the current, and one challenge is finding a place to put it ( about the size of an ANL fuse holder). You'll need to keep it safe, so maybe in a plastic project box with water-tight cabling connections.