So I believe the wiring is clipped somewhere along the circuitry leading off my alternator, just put a new one in two days ago, drove the 15 miles to advance and got it checked, everything was working fine. Next day drove the car for about an hour or so, started it on three occastions during the hour, car won't start. I put a voltmeter on the terminal of the alternator and grounded it to the chassis, I'm showing like 12.3v while the cars running. I'll have to DIY the alternator problem soon but I have a trip coming up.


So my question is, how long will a normal battery last driving on the highway?
B16A SiR tranny, so around 4300rpm on the road, no lights, no anything in the interior. The battery will only be powering the dizzy, ecu, fuel pump, and injectors. Interior is completely striped so just a seat and steering wheel, flip switch ignition, so the power demands are low.

I'm hoping it'll last around 1.5 - 2 hrs?! Engine braking and no use of the brake lights the entire trip hopefully....

 

You'd be real lucky to see 1 hour IMO....

The alternator has a 4 pin connector, remove the "C" pin and see if it charges, if it does then your ELD is bad.

 

Theres a black/yel, wht/blue, yellow, and wht/yel wire, which is the C slot, I'm away from the car for the next couple of hours at work, just trying to figure out the wiring..

 

The wire colors varied so much from year to year and model to model I couldn't begin to tell ya, sorry bro... If you have a haines or chilton manual I think it will say.

 

Alright, well if I can remember correctly theres a wire that goes directly to the ECU, one thats grounded, one that gets 12v once the ignition is moved to position two, and one the connects the battery indicator light. Theres two plugs on top that lay flat and two that run perpendicular to those, any ideas which is the C?

I just need power for around 4 hrs of driving, if I burn up the battery its got a three yr warranty, I just want to eliminate the need to tow my car ha

 

I do know for fact that the "C" pin when looking into the alternator is the horizontal pin on the top left

You have this when looking into the alt:

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The computer terminal is the one on the top left.

 

The terminals are:

"C" - Computer/ELD
"Fr" - Frequency/feedback to ECM
"Ig" - Ignition 12v
"L" - Indicator lamp in dash.

There is no ground that I'm aware of, except the ELD does switch the "C" terminal to ground in order to shut the alternator off when high load or demand is placed on the engine. Hope this helps

 

Alright thanks for your help. If I disconnect the ELD wire will it burn out the alternator or overcharge the battery? I'm not too worried about either, just so I know that they'll need to be replaced.

 

Nope, not at all. You just loose that function (alt shut off when throttle is over 75%) The alternator will charge as normal.

 

Cut the cord, car ran fine for about 3.5 hrs of the trip, battery finally got discharged too much and died. I guess it doesn't charge it at full capacity or something else is wrong.

Know where I can find the wiring diagram of the actual regulator circuitry inside the alternator?? I may just end up setting up an external regulator or something along those lines to bypass the ELD

 

I drove my Prelude with the alternator unplugged for probably 5 hours back in highschool (once it got dark and I had the headlights on for 5 mins they got super dim and the motor was chugging... got out and realized I'd forgotten to plug the alternator back in after Auto Shop class).

As for the regulator - I believe it's the large C-shaped IC inside the back cover. No clue how you'd bypass it but it's totally replaceable. Not much more work than changing the brushes.

 

No need to bypass the ELD or change regulators, just disconnect the "C" pin from the alternator plug and be done with it! it will charge and run just fine without it, you will only loose the WOT cutoff function.

Oh, and the large C shaped thing under the cover is the rectifier plate!! not the
regulator.

EDIT: sorry I didn't see where you said it only ran a few hours and then discharged... sounds like theres something else wrong with your charging system bro! cause pulling the C pin won;t hurt a thing.

 

Sorry I'm dragging this out, the wiring harness that I picked up for my car had plenty of little ghetto wiring additions and subtractions so a lot of the electrical issues have been because of wiring that the crimps came off. I've completely striped the interior of all the materials and wiring now essential to the operation of the engine. I believe the issue is somewhere within the wire looms under the intake manifold, maybe a loose wire somewhere.

Anyways, I realize I can make the alternator operate off three of the four wires, but I'm just going to clip the wires about ten inches from the alternator and rewire it. Looking at the alternator there is
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what needs to be powered, resisted, etc for each. Everything in the car is run off switches, headlights, ingnition, turn signals, fuel pump, etc. so its just a matter of getting the right setup.

I also heard the check battery light allows the alternator to energize....I'm planning on pulling the bulb and running a solid line in its place; I have a voltmeter, no reason for some dumb idiot light.

Thanks for all your help, thank god I have bus transportation near my house otherwise I'd be f***ed

 

You have "C" "Fr" "Ig" and "L". Terminals, the only two that need connected for the alternator to operate are the Ig (switched 12vdc) and the "L" which is just the dash indicator lamp. You can wire it direct to 12volts with a 250ohm resistor in series and be good to go!

 

We drove a corolla without an operational alternator for about 150-200km. We did that with one of those small japanese batteries. Craziest drive ever, foggy autum night, heater had to be on aswell as headlights, still managed to start it up the next morning and drive it to the garage too.

 

i traveled 35 km or .5 hrs with burned alt