2004 accord 2.4
Today I had a slow starter so I hooked up my volt meter to see what was going on while driving.

just normal driving, no charge, 12.5 volts but if
I put any kind of load on like AC, or headlights, or even the cooling fan turns on then it will charge the normal 13.7
also any speed above 45 and the charge sys kicks in.
any speed less than that it seems like it's not charging at all.
Is this normal?
or is something messed up?

my engine light came on about 2 days and 100 miles before todays issue but I just pulled the batt cable and the light went off.

 

The next time your check engine light turns on, stop by an auto parts store and have the code(s) read. The error code stored when the check engine light turns on can help identify what is up with your car.

The voltage from the alternator can range from about 12 to 14 volts depending on the sensors in the engine and power consumption from the a/c. When you stop by the parts store have them test the battery, alternator, and the starter as well.

 

Honda's ECU can control the alternator. When there's no electrical loads (per the ELD) and the battery voltage is good, it'll switch the alternator completely OFF to help improve MPG.