Is this voltage normal
Honda civic 2011 with 98k kms. My alternator just went out. I drove the car with the battery reading 12v. After turning it off the car wont start anymore. I changed my alternator, I measured the Battery immediately while the ewngine is running. 13.8 Volts, then I opened the ac headlights on then dropped to 13.1-13.4 is it normal. Note I immediately checked it after installing without waiting for the battery to be fully charged
Sounds like weak alternator but check the battery. Hook up volt meter to battery and crank car over. Watch the voltage as you crank it's possible your battery is screwed up. Also check your connections make sure everything is clean and tight as well
Honda civic 2011 98k kms. I have checked my alternator at idle. The Volts remain at 14 Volts when all accessories including headlights and Ac are on. BUT i noticed that when the Auxilliary Fan beside the Radiator fan kicks in, it momentarily drops to 13volts to 13.1 Volts then climbs back up to 14 after the fan kicks off . Note this is at idle speed of 800 rpm
when the Auxilliary Fan ... kicks in, it momentarily drops to 13volts
A stationary motor is basically a short circuit.
Is it normal?
#1 - It's normal as explained in the motor wiki article link I posted above.
#2 - Please try to keep all your related questions together in one topic. Thanks.
After turning it off the car wont start anymore
Are you still having this problem?
You normally do not check your voltage when idling. It is not really indicative, since cars, their alternators, and battery charging systems are not designed to support much load at idle. Cars are made for driving 😉
You can only tell whether or not your voltage situation is normal after you have checked your voltage in line with your specific car manufacturer´s voltage checking guidelines. Those are normally contained in the technical documentation for your car one can normally find in the Internet.
On most cars I know voltage is checked at 2000 RPM, and there are also specific conditions to be observed when doing this check (e.g. some electrical systems and devices have to be turned on, and some - off). Even temperature matters, since charging systems normally have temp compensation in them.
That the voltage drops when powerful devices (like headlamps) get turned on, is absolutely normal.
P.S. At first glance, the voltage figures you mentioned sound ok to me.
With the battery fully charged and the engine idling with all accessories off, the voltage at the battery should be very close to 14.5 volts.