Hi, I've got a 92 civic cx with a chipped ECU and was wondering why I am getting 15-16v with the car on. The car did this for a few months before the alternator died. I put a brand new battery and alternator in, and it still was charging at 15-16v. Any ideas? Bad ECU maybe?

 

it's possible, but doubtful. the regulator in the alternator regulates the voltage.

make sure that your grounds are good.
Take the alternator back to the store and have it checked.

if that doesn't fix it try another ECU. Any OBD1 honda ECU will work long enough to check if it fixes it.

 

There is also a mysterious little device called the electrical load detector, or ELD. Not a lot of documention available for it. Might have some role in the problem, assuming your meter is calibrated correctly.

 

ELD = basically a coil wrapped around the main battery line. It's used to determine how much power is being pulled from the battery to determine the coil intensity of the alternator and if the idle should be raised or not.

not really a mystery, more of a commonly misinterpreted part.

Typical symptoms when it fails, high idle, low idle, choppy idle, low voltage on battery at idle.

 

the models that shipped to canada weren't equipped with ELDs

 

That sounds exactly like what the problem is... but I don't know if my car has one. Its a 92 CX from canada. I will look at it tonight when I get home. Thanks everyone!