Constant battery drain, won't crank without charging. Good batt, ALT and starter. Regal GS

ATRIAVENTRICA

MEMBER
1995 BUICK REGAL
157,000 MILES

I changed my starter a while ago and haven't had any problems for the longest time. Then over time it became harder and harder to start. Eventually it wont start but once its jumped it'll drive forever (hours at a time) but as soon as you turn it off it won't start again without a jump. Got my battery tested and its good, alternators putting out 14 amps, starters still brand new and good. There's a drain somewhere of course, I'm sure of it, but I don't have a multimeter (nor would I know what to do with it if I did). My ABS light is on now but my fluid levels are good so I don't know if that's an indication of where the short is? Also, if in the interim I buy a jump starter, how do I know how big to go? Will 400 amps do for a 3.8 V6 if the battery is still mostly charged?

1 Reply

WRENCHTECH

MECHANIC
20,757 POSTS

400 CCA is too small for most situations. You would have no reserve at all. Get at least 550.

There is a procedure for finding a battery draw like that.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.