battery light :S

[nath106]

right basically for people that know i have a 106 xsi with gti conversion

had a running problem ever since i did the conversion, the car will start no problem at all, first time every time.

now when i start it the engine management light goes off as it should aswell as any other lights

i can then rev it once, at which it will rev perfectly normal

but after that the battery light comes on. not bright but dull, as soon as this happens the car goes lumpy and then has the usual problem, it wont rev very well, is lumpy and seems astho it has a slight miss

any1 got any ideas?

im guna clean battery terminals tomorrow, and check the two earths underneath it (bolted to chassis)

the battery itself has been put on trickle charge over night 2 days ago, i will prob do it again tonight

[stalkah66]

Could be the alternator have you checked the output?

[brooksy22]

could be the alternator on its way out or a lose earth wire

[steve_335]

Sounds like an altenator, i had that in a car, battery light was on, changed alternator and sorted it

[nath106]

every1 atm seems to be pointing towards alternator

but would an alternator (even if its fukd) cause my car to suddenly start fueling incorrectly or whatever its doing?

will be putting voltmeter across battery tomorrow and its on trickle charge now

[Arr0nUK]

as everyone else said alternator

though your wiring or something could be messed up and something else is taking a lot of the battery charge

just an ideal

[nath106]

yeh mate it could well be my wiring

i had to run a separate feed for the fuel pump off of pin number 3 on my coilpack i think so that its a switched live

but when i rev it the light comes on after about 5seconds of being back on idle it goes off again

im hoping its the alternator as its an easy fix, where as tracing through all my wiring again just really isnt fun and i know i double even triple checked it all. its just the fuse box wiring that could be wrong imo as any guide on the net wasnt clear

ie 122 goes in with the 120's ....wtf?

[nath106]

well the connections on the alternator dont seem to be burnt out...?

as they are just metal rings that bolt to the alternator, wires dont seem burnt either, maybe ill strip them back and check them over weekend as im working allday from 4

i checked the voltage across the battery

when car is running (no light on dash) 14-15volts
when car is running (light on dash) 18.5-19volts
when car is running (after light has gone out) 19volts

when car isnt running 16volts

[nath106]

also...

can i put my spare 1.1 106 alternator on there to see if that changes anything??

[nath106]

my multimeter was definately on the right settings, black on the com port and the red on the v side

put it onto a 9v battery and it read 11.5v

if its out by 2.5v then my readings across the battery when

engine on light off would be around 12.5-13v
engine on light on would be around 16.5-17v

which is more realistic

the light seems to come on at around 2250rpm no matter what gear you are in, after its come on for the first time (causing the car to run shit even when its gone back out) i can then rev the car past that point and it wont come on again??

its weird imo as i cant understand why the it suddenly comes on at thta point and then even when it goes out the ecu is still having a headfuk??

[betty]

when your fan belt is on its way out some cars show the battery light but it could also be alternator hope this helps
claire
a.k.a betty x

[nath106]

i hope it aint cambelt!

the light only seems to come on if revved over 2250rpm????

cambelt seemed good when rebuilt the head