Battery is 12.6 volts and when the engine is turned on it stays around 11.2-11.5v. I took the alternator to get tested and tested fine. All new cables are being used. 8g to the alt to ecu. I cconneced the battery to my friends running car and tried to start. It was at 12v+ while running and battery light still on. Any ideas? I've added numerous ground. Including a separate ground from battery to ecu thermostat ground. It has a rough iidle without the car being jumped. The car seemed to run alot smoother with the 2 cars linked up. Any idea?

 

Old Fords will not field the coil until 11.5V from my experience.

 

I'm still trying to figure out what kind of car the OP has.

 

did you get the battery tested?

 

Sorry fellas for the lack of information. Its a 1990 integra converted to OBD1. The battery is a new Odyssey PC680. The alt is a rebuilt one ive use for about 3 years. it worked fine when i started this build and i got it tested when this problem came up. Someone told be autozone and similar places are bad at testing these. ? That doesnt make sense to me although. When i had another car jumped to the battery it ran smoother but the battery light was still on. I noticed if i where to jump my other acura the battery light would not stay on. I was thinking maybe the light was being lit up do to OVER charging. but thats not the case. I understand the battery is grounded to the bracket its being held on. I will add a ground from the battery to the bracket and see if i get anything.

Im half temped to throw a new alt. but i would be throwing money and it and Crossing my fingers.

 

If the car is only seeing 11v with the car running then it makes most sense that the alternator is bad.

Your best bet is a Denso reman from rockauto if they have one for your car.

 

I would start by verifying the wiring for the alternator charge circuit and control circuits.

Has this configuration ever worked? I would estimate, again based on limited input from you, that you have a wiring problem to address. If I'm not mistaken, OBD1 Honda's all use an ELD. Not sure about Pre-OBD Honda's. This would be something to look into.

 

Even if there is an issue with the ELD circuit it's going to run in full output mode. The ELD's only function is to allow the car to run in low output mode to save gas.

I suppose you can first check that the 80a fuse in the fuse box assembly isn't blown.

 

Your right it, it did throw ELD code #20. i should mention that I'm running a hondata s300 v2. It had the option in the to disable the ELD. Its running a p28 basemap . I replaced my battery cables and alternator charge cable with new 8ga I bought from the local battery supply store. Its routed same as factory. Alt to fuse box, then fuse box to battery, that's relocated to the top three back. I have a new 4ga wire from the battery to starter.

-I've checked and double checked all the fuses. .