My car randomly would not start a few weeks ago.. jumped the battery from a friends car and after a few minutes, the car started right up......i let the car idle for about 5 minutes, drove around for 10 min, then took it home.....let it sit for awhile, went to start it back up and nothing.......now the battery had enough juice to run the electric components (radio, headlights etc), but enough to start the car....So i took the battery to get tested, they told me it was bad (130 CCA)...so i bought a new battery and everything seemed fine until 2 days ago...car's not starting, but elec accessories still operate fine with engine off.....a friend of mine had a spare alt from an 88...we swapped in that alt, jumped the battery .....turned right on after a few minutes. upon start up, the voltage reading was healthy..... we drove the car around for about (this is at nite btw).....as we started driving, we noticed the voltage started to fall.....Any electrical load (like applying the brakes) would cause the voltage to drop drastically (like to 7- 8 volts)..........we parked the car, shut it down, then tried to restart, then nothing..............later that nite another friend of mine jumped my battery again(so i could move my car) however, this time, we jumped my battery for a few more minutes. when i drove the car this time, the voltage wasnt dropping anymore and the voltage would read about 13v at idle and would raise slightly while driving....on a side note, as it stands right now, if i turn the key to the on position, the voltage reads about 10, if i go to start the engine, the voltage drops and the engine fails to start....subsequent attempts show lower 'on' voltage readings.......so i have 2 questions. How long should a battery be jumped before disconnecting it and driving? And 2 batteries and 2 alts seemed to give me the same problem...any ideas? I guess my friends spare alt couldve been bad......any ideas are appreciated thanx....if searched this topic and ive read numerous posts concerning others issues...just trying to get some input

 

Its not your alternator. Make sure your battery,and terminals are not corroded and are tight on the battery. If they are corroded clean them as best as possible (you should see the terminals shine) if that doesnt do it. then replace both terminals. They are like $3.00 each. Hope this helps.

-Rich

 

Its not your alternator. Make sure your battery,and terminals are not corroded and are tight on the battery. If they are corroded clean them as best as possible (you should see the terminals shine) if that doesnt do it. then replace both terminals. They are like $3.00 each. Hope this helps.

-Rich

 

So you're saying my 3 week old battery is shot? Since its not the alternator?...I just tested the voltage of the battery with a multimeter....its registered 12.4V...

 

i am having this exact same issue.
New alternator
New battery
Cleaned the ground terminals and sanded off some paint with sand paper.

And now its not starting again ><

Im thinking about just running new ground wires. I can't think of what else is wrong =\

 

when you say that it doesnt start, what does it do? does the engine just kick over very slowly, or does it not spin at all? Does the voltage drop a lot when you try?

Dirty/corroded terminals can cause this problem and actually sap a lot of voltage. Pull the terminals off, clean up the posts on the battery and the inside of the terminal blocks with sandpaper, and put them back on. Do the same with the thick wire that bolts onto the back of the starter, and with the main ground strap that goes from the battery to the upper bolt holding the starter on. Apply dielectric grease (some places sell this as bulb grease) to all connections to keep them from corroding again.

 

my car turned over VERY slowly and wouldnt start. my parents stole it and took it to a mechanic......
i think this is gunna be a spensive........

 

turned out to be the E-Fan was rigged to run on max power all the time and was causing a hellacious draw on the amps. It started melting wires... so with all that fixed it runs great once again!