check the black wire yellow stripe near alternator. I had a short there once and took me months to find it. Basically 15A ECU fuse will blow and then alternator will not get a signal to charge the battery.


But I agree with what has already been said with a good battery and no alternator you should be able to drive around for 30 mins or so in power saving mode.

 

Ok so when I start my car on a battery charger its completely fine but when I take the charger off my battery starts to drain. Slowly, and its stalls out when im down to 5 volts of the battery, when my engine fires I need my battery charger to fire the car up and then I can take the charger off and then its starts to drain, but if I turn off my car and pull the key out the battery read 12 volts, but when I put the key back in it my battery is completely drains and I camt fire it up. So yes I have to jump ky battery every time I want to start my car and I bought a new negative cord and alternator

 

It will let me drive like 20 miles and then no more battery and is this 15 fuse in my engine bay fuse box or in the car fuse box?

 

In car. Assuming this is a 2001. AT? 4cyl?

 

Is your CEL on?

 

If it's charging at 14.20 when your car is running then it's charging fine(even if this is when the car is warmed up and the rpms are only 750 as opposed to 1500). However, it woulda been nice to have you actually do the test when the headlights were on as well. If, when you turn off the car, the battery is already at 12.00 then the car isn't holding a charge which means it's going bad or already is there.


Keep in mind that Honda uses a dual mode charging system. Until the car is warmed up the charging system will charge in full output. After it's warmed up and below 40mph with no loads on, the car will charge at 12.60. Also, it makes peak power at 1500+ rpms.

That's why you test the charging system when it's cold, when the idle is 1500 and it's running in full output.

You can take your battery down to the parts store and they will check it for free. Just do that.

 

Jwolfe it a 94 manual 4cyl and as of yesterday all my dash light work and now they dont, I did the jump test to see what code for the cel and it gave me a solid single light so idk and im gna take my battery to advance to check it thank you

 

Holmesnmanny I checked my battery and they said it was alittle weak but good and I rechecked the alternator to see if they gave me a bad one and that one came out good. Now im going to replace the pigtail on the alternator end and see how that goes. Any other suggestions?

 

It sounds like a bad battery to me.

 

Let the car completely cool down. Check voltage across the battery posts. Note it. Start car. It should be idling at 1500. If not, let car completely cool down. Start car. Note voltage across battery posts. Turn on headlights. Note voltage. Turn on rear defogger(while headlights still on). Note voltage. Turn car off. Note voltage. Start car and drive 10 miles or so. Turn car off. Note voltage.

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