the other day, i went to leave work and my car wouldnt start, it cranked really slow and then died. i rolling pop started it and shut my stereo off for the ride home. it ran fine the whole way home, about an hour. i still have not turned on my stereo for 3 days, and my car starts fine every time and actually cranks faster and starts easier than ever. i have my battery mounted in the trunk and grounded in the back on the chassis. i have a small amp mounted in the trunk and the ground is run back to the negative on the battery. am i causing a ground loop? should i check the ground on the headunit? this is weird. any help is appreciated. thanks.

okay. i have not since turned on my radio and unhooked the amp. I also went and got a new big-ass battery. i have also checked the ground wire in the back. it still is sometimes having problems wanting to crank fast enough to start though. so today i busted out the multimeter. the battery shows 12.75. plenty. i then started the car and checked the battery voltage, slowly rising to a peak of 13.05. I then checked the alternator output with various different grounds, still only 13 tops!!. is my alternator on the way out? the belt is tight, i checked.

what's the voltage reading when trying to start the car? Does it drop below 12V? I've had a similiar issue and it was related to the size of cable (my case it was 4 gauge wire) being used.

what size wire are you using for your relocated battery?

i didn't check the voltage when starting, I'll try that tommorrow. as of the guage wire, let me go check.

i just looked at the wire size. it doesnt say what size, but it is roughly one size larger(or double) than the 4 guage used for my stereo. i'm guessing 2guage(if there is such). it is red with thick black lines running down it. the ground cable is the same size only solid black.

i would assume the wire is heavy enough. it is the same size that runs from the battery to the starter with the battery mounted under the hood

when i was checking the voltage output on the alternator, i even grounded it to itself. still only about 13.05, 13.06. voltage output should be at least high 13s, and that is still low.

today at work i checked the voltage when trying to start the car. the multimeter at work was jacked-up, so i couldn't tell exactly what voltages it read. but the volts didnt drop under 12 when starting, they actually went up a little.