ch ch ch ch noise on start up - alternator?

[timmy_tam]

got a vn 91 calais
lately, on start up, it makes a ch ch ch ch noise
went for about 30 seconds
i can see the alternator just flicking, sorta like it's seized

when off, the battery is about 12.15 v
when on, the battery is still around 12.8 v

does that mean the alternator is stuffed?
or could it be more, such as starter motor?

what does a new alternator cost?

[88GreenVN]

Belts and pullies OK? Brushes in the alt can cause the alt light to flicker.

[timmy_tam]

the alt light on the cluster dash?
haven't seen it
what does it look like?
and do u mean the brushes inside the alternator itself?

[88GreenVN]

[QUOTE=timmy_tam;462534]
i can see the alternator just flicking, sorta like it's seizedQUOTE]

What do you mean by this?? When the car is running - what part flickers. I was thinking the alt light in the dash. but from your reply that may not be the case....

[VNV6VENGEANCE]

he means the fins and the belt. Mine does it occasionally. It can come from all sorts of things. A retardation of the ignition timing caused usually by leads. Check lead votlage. then get back to us.

[timmy_tam]

yeh, thats right
the fins on teh alternator
how do i check the lead voltages?
disconnect the lead, put the positve of voltimeter to lead and negative to ground?

could it be spark plugs?
i keep thinking it's alternator...?

[timmy_tam]

okay, i've gone and cleaned all the battery connectsion back to bare metal, inclduing the connection at the back of the alternator at the suggestion of a member on JC
and it seemed to work, car started up normal again
but just now, it started doing it again, the ch ch ch on start up

i'm pretty stumped, anyone have any ideas?

[JD]

go to a wreckers pick yourself up another one they only cost around $20
less screwing around

[timmy_tam]

okay, turned out to be oxidised connection at back of the alternator, which was draining my battery on start up
a 10 mm spanner, sand paper, conductive grease and a recharge had the vn baby purring like a tiger again

thanks VT97

[88GreenVN]

Good old grease on the connector - good for battery terminals too.

[vks]

when the engine is running and the alternator is charging the batt should be up round 14 or 15V.

[88GreenVN]

when the engine is running and the alternator is charging the batt should be up round 14 or 15V.

Did the test on the L3 dash and got 13.9v - that the one that gives you the digital speedo on the VN and pressed mode 1 time to get the volts.

[defa]

wouldn't want to have it charging at 15..14 is any amount..