Finding Electrical Drain

[W0rp3D]

I was having a problem with my old battery not charging so i bought i brand new red top and replaced the alternator, was perfect for a while but now it has slowly gone back to the old problem, turns over slow and sometimes wont start at all, the only volt gauge i have in the car is my pioneer head unit, it shows 13.7-14 with every thing off and the radio turned down so the amp isnt using much power and with the climate control on, headlights on and stereo at normal volume drops to about 13 - 13.4, when i turn the stereo up with the bass going none of the lights dim or anything like that.

A couple of times it has started fine then after driving for 5-10 minutes i park it for a couple of minutes then get back in and it wont start.

The two problems im thinking is the starter motor drainging a lot of power, this would also be why after a short run i cant start it, it drains so much power and i have not driven it long enough to get back in.

Or my alarm is draining it, either way how do i check to see what is draining power?

[infamous_t]

Auto sparky can do it, but if you want to... get urself a clampmeter to measure amp discharge while car is off.

One by one go thru your fuses and remove them and see if it changes amp discharge

Make note of any that do and then check to see if they are shorting or on when they shouldn't be (ie fuel pump staying on when should be off with car etc.)

Normal discharge with an alarm with everything thing of should be around 0.5amp (1amp tops).

EDIT: Just read thru properly, battery voltage is fine, infact nearly full. I'd be looking at earth straps & starter motor

[116.hks]

hey mate.. the current draw drain on any vehicle is no large then 0.01 - 0.05. any greater then that is enough to drain a battery overnite especially if you are doing short trips and stop starting alot. i usually tell my customers at work if the battery is flat either drive the vehicle through peak hour traffic or put on a charger overnite. the only vehicles that i have seen with a larger current draw are late model jags, mercs ect due to the amount of body control modules. the most common problem i've seen through my workshop when the battery is going flat is due to incorrect aftermarket fitment. eg stereo, alarms, computers even faulty alt etc. as i'm an auto elect by trade i would say take back to the person you got the alt done through and ask for a current draw check. hope this helps