UK Car Repair: Re: battery draining, auto electrician, faulty circuit


Question
Hi Chris,
What do think:
The battery on my Sedona drained overnite 2 weeks ago, it wouldnt start, Rac told me I needed a new battery.
Got one fitted at £120 at local garage, then recently I started having the same problems, sluggish on starting. So something was clearly draining it.

So took it to an auto electrician, now its been ascertained, its the alternator, he's managed to source one for £189, but the total is still £310 inc  labor................

Expensive....

Do think its definately the alternator or is my sparky trying to get some xtra cash!

The good news is the guy who fitted the battery is willing to buy the new one back!

Answer
if it was a bad alternator it would drain whilst driving, not overnight - think captain slow running out of electricity- unless, exceptionally, the alternator works while driving but drains while sitting.

you need a multimeter to check each circuit for drain (19.99 from argos).

put the -lead to battery- and the +lead on each fuses exposed metal(either side) in turn.
have the meter set to 500ma range (milliamps, to measure CURRENT).

When you find a fuse drawing something over 50ma you have found your faulty circuit. it could be the altrnator but I'm far from convinced.

when you know where the drain is and how much I can help further or you can get onto a garage with the required ammo.


check for things like glovebox/boot/door lights staying on if not willing to buy+dig around with a multimeter.