DanS

Drove my car home after having the new Gearbox fitted (thanks Bernie and SCC ) and noticed some very strange things things happen when i turned my heater on/off.

I've just fitted a new cossie pump which has a louder buzz compared to the std RST one (which is probably why i've only just noticed the problem), but when i turned my heater on and off the buzz tone would drop for fraction of a second. I also noticed this when it started from cold later that day, every time the car hunted and revs dropped the buzz from the pump also changed note.

So volt meter out.....

Volts from Altornator @ idle 14.13 (holds this value when engine revs increase)
Volts from Batt @ Idle 14.1 (holds this value when engine revs increase)
But when i turn my heater on it drops to around 13.7 @ the alternator.

I then checked the fuel pump, 14v @ idle but when i flick the heater on and off it dropped again to 13.7 and the pump buzzing sound dropped and picked up again.

I've checked all earths and as much wiring as possible and seems all ok. Does this sound like a dodgy alternator regulator? I've recently fitted a new reconditioned alternator could this be faulty?

Cheers,
Dan

gingeRS

i'm guessing the heater fan is drawing too mcuh current, check the terminals on the top of it as they go all rusty and nasty.

also check where the heater blower earths on the windscreen wiper motor mount

Lambchop

iTrader: (1)

very interested in whether its the alternator reg because im having probs with my cossie at the mo...

DanS

I will check that. But the voltage seemed to drop when the car was "hunting" from cold which tends to suggest the alternator?

Rick

ur worrying over nothing. the battery voltage will always drop when u place load on it. The pump is a motor, and will turn faster or slower depending on how much voltage it sees. At low rpm, the alternator is not at full capacity, so any slight change in engine rpm will cause a change in voltage. Turn your headlights on, heated screen etc and you will also see another drop in voltage. Normal.

DanS

I've never noticed it before, only since fitting the cossie pump which is much louder. Still no harm in sticking a fuel pressure gauge on it to check.

Whats the dangerous voltage level then? sub 12?

DanS