Vauxhall Astra new altinator and new battery but still a wrong battery voltage
Variant: 1.6 8valve
Model Year: 1992
Categories:
Electrics, ECU, Warnings & Lights
Car wouldn't start,had a friend look it over.
Took voltage reading from battery, got a reading which was to high and when you revved it up got higher.
We tried it with a different battery and got the same problem.
so we changed the Altinator.
We checked again and the voltage was to low. around 9v
So we assumed it must be the battery draining to much power so we fitted a new battery.
We checked again and now the voltage is reading steady but still too low at 12v in idle.
Any ideas would be highly appreciated!
Ash
Took voltage reading from battery, got a reading which was to high and when you revved it up got higher.
We tried it with a different battery and got the same problem.
so we changed the Altinator.
We checked again and the voltage was to low. around 9v
So we assumed it must be the battery draining to much power so we fitted a new battery.
We checked again and now the voltage is reading steady but still too low at 12v in idle.
Any ideas would be highly appreciated!
Ash
Posted: Dec 31, 2011 (12 years ago)
Alternator is not charging . Either dud alternator or a fault with wiring / connector / plug .
Posted Dec 31, 2011 (12 years ago)
what happens to the voltage reading if you load up the battery at idle? i.e interior fan and lights on.
Posted Dec 31, 2011 (12 years ago)
When we changed the altinator the first time it did'nt work so we changed it for a second thinking we might have been supplied with a fautly altinator but it didnt change anything. I think my friend took a resistance reading across the cable from the altinator to the battery and it was about 1 ohme.
When you turn on the lights inside the car etc. the battery voltage reading goes down. from 12.42 to around 12.26
thanks for the speedy reply!
When you turn on the lights inside the car etc. the battery voltage reading goes down. from 12.42 to around 12.26
thanks for the speedy reply!
Posted Dec 31, 2011 (12 years ago)
Your alternator is not charging .If you put on heated rear window , headlights , heater motor it will probably show a discharge .
Posted Dec 31, 2011 (12 years ago)
Get a SINGLE jump lead,connect it to battery negative and other end to clean good metal on the gearbox/engine and retest the voltage.
This will rule out or in the engine/gearbox earth strap.
If the voltage is now normal then the earth strap has a high resistance,renew it.
This will rule out or in the engine/gearbox earth strap.
If the voltage is now normal then the earth strap has a high resistance,renew it.
Posted Jan 1, 2012 (12 years ago)
We did your test 1/4Drive and the earth strap seems to be ok so thanks for helping us rule that out.
We checked it again with it loaded and unloaded with lights etc and again there was fluxuation.
However this is the 2nd new alternator we have fitted in the car so perhaps when we returned the first new one as faulty to the shop they swapped the boxes and gave us it back.
We checked it again with it loaded and unloaded with lights etc and again there was fluxuation.
However this is the 2nd new alternator we have fitted in the car so perhaps when we returned the first new one as faulty to the shop they swapped the boxes and gave us it back.
Posted Jan 1, 2012 (12 years ago)
three things
did you change the alt belt
is the new alt correct amp
did it come with a new puley or did you re-fit the old one
all these can affect the charge rate
did you change the alt belt
is the new alt correct amp
did it come with a new puley or did you re-fit the old one
all these can affect the charge rate
Posted Jan 2, 2012 (12 years ago)
This problem is archived
If you're having a similar problem please click below to re-post this problem, you can then customise it to suit your situation.
Join the community
Got a question? Can you answer other questions here? If so please...
Astra Recalls (13)
Parts mentioned