Diagnose My Car

2005 Honda Civic

My night goes as follows (My Gf’s Birthday)

I drive there, we eat dinner, We drive to her friends, pick her up and go to the store.

Here it begins:

  • Car wouldn’t start, battery is dead.

  • We get it boosted.

We drive her friend home and I go to drop her off, waiting with the car ON in the parked position, the car dies. Try to start it, battery is dead.

- We get it boosted.

Driving home I notice the RPM in the park or neutral position are only 700-800 rpms, MUCH lower, they used to be around 1500.

- Stuck in traffic, Drive, go to neutral, parking break, gas to keep above 2000rms so car dosnt stop again. Repeat x600 times on the way home.

- I get home, cars in driveway, on and parked. I notice the low RPMS again, my headlights start flickering. I turn car off, dosn’t turn back on. Dead battery.

All this happened within a 2 hour timeframe.

Im thinking a shit battery that won’t hold charge anymore, but would that explain the low RPM’s? Also why would the battery have died in the first place when I went to the store? It was only like 30 min and I didnt leave any lights or anything on?

Please help.

Check if alternator belt is loose! IF not get alternator tested, cause its not charging battery proper!

Change:

Alternator and Battery!!

Would the alternator cause the RPM issue? :S

yes lost of power

Check the alternator fuse make sure its not fried

Boost the car and make sure it will run on its own power for 2 minutes for this test. Let the boosting car charge yours for a few minutes if you have to or use a battery charger to charge yours before this test.

After you disconnect the two cars from boosting or charging pull the positive terminal off the battery while the cars running and if the car instantly dies its something related to your alternator. A decently working alternator will keep your car running without a battery fyi.

I doubt your battery is the cause of the issue since your car should still run even no battery at all. Your cars likley sucking the juice out of that battery which is not getting charged by the alternator.

Ok thanks a lot, ill test it tomorrow, and if need be change the alternator, and probably battery along with it.

Easy way to tell. Throw a volt meter on the battery, should be 12V, then switch the multimeter to amps, and look how many CCA (cold cranking amps your battery should have) while the starters cranking if its lower then what the spec says it should be, your battery’s fucked. If not, then get someone to boost the car, start it and go back to Volts on the multimeter and if it doesn’t say close 13.8 volts while the car is running it’ll be your alternator.

not totally correct. when the battery is fully charged you should have 12.6v. Under cranking a 4cyl won’t usually draw more than 100a. get the car started and check what the voltage is at the battery. should be charging anywhere from 13-14v.

Yeah 12.6V. I knew I missed a decimal there. :lol: Good luck and pm me if anything.

Sounds like a shorted cell inside the battery.
No care will run proper with alternating voltage surges.

Get the battery tested properly.

Report back.

yes i would agree, but if the car was running off the battery for a while because of a dead alt, the only thing keeping the car going was the battery which would eventually die, and would do exactly what he is describing.

Update:

Fixed

Tested the alternator, a bit weak compared to OEM about 8% loss of power of the years, no problems there.

Battery: Charging at like 9v :S

Bought a brand new battery, replaced dead brake light, vacuumed up french fries.

Good as new.

Thank you to everyone for the advice!

so the french fries were the problem…spread the word on mayo!!!

Note: McDonalds is bad for cars too.

On a funnier note, as of that day I wen’t back to being Vegetarian.

hope you did a full test after the new battery was installed, to double check alt. is it an aftermarket alt currently? nothing but trouble :frowning:

^ OEM alternator works fine still :slight_smile: