Linville33

Ok so my car sat for two days while i had to replace a caliper. When i got in it to leave i went to start it and everything inside came on(radio, Dash Lights, LEDs) But it was bogging down as if the battery was dead. In the last three days it has done this twice. Any advice would be greatly appreciated.

dacrxguy

you can get your charging system/battery checked at many automotive parts sellers for free.

CRX Toad

If you have a multimeter you can test it yourself from the alt to battery

Linville33

If i use a multimeter what wires am i testing? Pictures would be great

pandarex

iTrader: (1)

With the car running place the multimeter probes on the positive and neg of the battery terminals. You should be getting around 14 volts.

Former User

So the engine starts but runs poorly?

Any CEL codes?

KINGVEM^^ED6

iTrader: (1)

With multi meter check battery with car off it should be 12.4 iirc volts if not its battery (if it is proceed to nxt step)

While running it should be 14 if not its alt

G-Man66

Does it idle slowly as well?

jchope

im kinda haveing the same problem but i drive for a little bit park and 5 mins later the car car wont start turn over or do anything

Exelbaradin

turn the car on and while running disconnect the positive terminal and if the car shuts off your alternator isnt charging enough if it stays on then go to autozone and get your battery checked

dacrxguy

Do not do this this is not safe for the electronics in the car.

jchope

ive done it many times and had no problem how would you recommend checking the alternator without taking it off

MRZCCRX

iTrader: (1)

^^^^^^^ Totally agree do not disconnect the battery while the car is running

4drEF

Done it many times as well without an issue.
Not the wisest thing I have done, but oh well.

The alternator does have potential to do a momentary spike and blow out electronics.
You CAN still fry an ECU or the car stereo. It's completely possible,
You can even fry the diodes in the alternator itself.

The theory is that if you disconnect the battery with the engine running, then the alternator will take over to keep the engine running.
If the engine dies, then the alternator is supposedly bad.
The downside is that if the engine stops running, then the alternator might be perfectly fine and you just blew out the ECU.

Former User

Compare voltage across the two battery posts under these three conditions:

1) Engine off -- should be ~12.5V to 13V

2) Warm engine idling with all electrical accessories off (no electrical load) -- should be ~14.2V to 14.4V

3) Warm engine idling with high beams on, A/C on, and cabin fan on high (high electrical load) -- should be ~13.9V to 14.2V