i got a 03 mustang v6 3.8, changed battery and alternator,worked properly for several days now its dead again.anyone got some suggestions on what could be the problem???

 

Bad cable from the alternator to the battery. Something may not be shutting off and is draining your battery over time. Could be several problems.

 

check the voltage... with the car off the battery should be at about 12V...with the car on the battery should be at about 14V anything less and while the car is on and there's a good chance it's the alternator.

 

Hi

I would check draw on battery. Use amp meter in seriers with battery and see what it draws in off position. If more than .1 amp to .2, pull a fuse at a time till it drops below .2 amp. Check all fuses. Correct me if I am wrong but your car is drawing power in the off position. Short etc. Fuses tell you where you may have a problem.

Regards

Brian

 

Check battery voltage with engine running should be 14-15 volts, anything less than 13.5 volts means there is a problem with the charging circuit, did you replace the voltage regulator as well?.

Check battery current with nothing (electrical) on, should be about 100-200 MA (0.1-0.2 amps), anything more & you have a problem with battery drain , you will need to find out where it's from ,the fuse trick is a good starting point. 1 amp draw would drain about 50% of your battery charge in 24 hrs, you would need a 1-2 hour (say) drive to top it up again, not a good situation, especially in cold weather..

 

if you are looking for a good alternator, or a stronger one than stock, check out alterstart.com. they got ones that put out a LOT of ampos....it would be great for those who are looking for a stronger one, say, if you have an underdrive pulley, or a high power sound system.

 

Hi

Missed the . on my previous post and he is correct. The CPU will draw and I have heard that a radio on will as well ?? Try off on radio. Should show up on my isolation sequence. .1 amp to .2amp is range to go for.

Brian