Battery or alternator? E46 330i

Jason330i

Member
Hi guys so i had my car die and pushed home on friday night..
Bought a duracell 652 battery on saturday but my battery light didnt go off and yesterday the car died again so i took it to them this morning and they said its a bad cell.
So they put a new battery in and battery light still didnt go off.. now according to the test on the OBC my battery is on 10volts again.
Any advice? Oh and i put a new alternator in about 3months ago
 

ET was here

New member
I believe that the battery light is a direct function of the alternator/voltage regulator
thus if the battery keeps on getting flat, and the battery light doesn't come on, then your problem is not the batery, but the alternator or voltage regulator
 

Dr Evil

Active member
When i had my e46 i had the same problem, the battery indicator on the dash is for the alternator, it's not charging the battery.

Sent from my G3 using my finger
 

Iceman007

Active member
Buy a regulator I got mine from SparXX back in the days for they were the cheapest for a genuine Bosch regulator. I fitted it and no further problems. Dont go for a pirate it gave me problems.
 

Karthik

New member
Check your cables firstly that are connecting to the battery, I had a faulty cable running power from the alternator back to the battery a few years ago. Small fix, though I never had any lights on the dash so might be your alternator.
 

Jason330i

Member
Ok thanks guys... so car got stuck in cape town cbd and my radiator hoses burst... just water everywhere[SEE-NO-EVIL MONKEY][SEE-NO-EVIL MONKEY]... so battery or alternator and cooling system
 

Pho3niX90

///Member
Yeah if the battery light is illuminated it means it's not charging properly or not at all.

Sonce the alternator is new take the car back if you had someone fit it, quick test is to take a multimeter and test the voltage on idle. It is likely that the ground wire is loose or damaged as it is a common thing on the E46s. But for now take it back.

Sent from my SM-N9005 using Tapatalk
 

Jason330i

Member
On the belt topic... my old battery the light wasnt on until i accelerated harder then the light came on and off as i accelerated
 

AcidBurn

Member
this sounds more like the voltage regulator on the alternator.

dont drive the car and have the alternator seen to and tested ASAP.

its a pity you wasted money on getting a new battery, you should of checked here first before buying a new battery. No you going to have to spend twice where you could of spent on the alternator only.

I hope for your sake you have the Bosch alternator and the Valeo one, as the Bosch one can be repaired and not the Valeo one. If you have the Valeo you need a new alternator which will set you back a few thousand ;(.

I replaced my voltage regulator about 1.5-2 years back and i purchased it from Bosch in Montague Gardens paid R750 for it.

Good Luck bud.
 
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