alternator, please help!!

[greg1.4]

got a problem.. my nova will not start, turning over very slow until nothing. i can put jump leads onto it from another car and she will fire up no probs.

i swapped the alternator (dont know if the new one works) but its still not starting.. i also checked my earth points, gearbox to chassis, brown wire near coil, brown wire from inlet manifold to alternator bracket and i think thats it. have i missed any? oh and one to the bulkhead from the neg terminal. i have a 1400 spi with a 1300 head and twin 40 carbs.. i have an earth wire disconected from the spi loom which has just been disconected from the engine/carb and is left lying in the engine bay so the ecu is still there.. should this stop if from running but surely its just an SR now without that wire originally if you know what i mean.

on the alternator i have got the brown eart from the inlet manifold then onto the alternator bracket bolt, the red live to the big terminal on the alternator and a blue and yellow i think it is. are these the only wires that should be going to it? if not what am i missing? is the blue and yellow wire going to the small terminal on the alternator for the battery light?

any help will be much appreciated as i need this fixed for an event tomorow.

cheers,
Greg

[Adam]

The blue and white goes to the clocks, for the battery light yeah.

Tried changing the starter motor? I had a very similar problem on my old engine, it would turn over mega slowly, and then just not crank at all. Even with another starter motor.
So i removed the motor, cleaned the mounting up where it touches the gearbox(so it gets a good earth), and changed the solenoid.
And that sorted it.

[greg1.4]

abit more info.. i have put a multimeter onto the battery and its reading 10.18volts when its started, then when i rev it it still doesnt go up.. i have checked for power to the live alternator and its getting 11.08 to it..

i have had a problem ith the starter before and i changed it (pain in the ****) and it was turning over very slow then not turning over atal but when i bump started it she started fine.. so i changed the starter and think that cured it as it was starting fine for months.

i have also got a transit van battery in it, will this have anything to do with it? i just put it in til i got a new nova one as the transit battery was good but not being used.

Greg

[Adam]

Sounds like the batts fooked.
10.18volts is too low.

[greg1.4]

the battery should still charge should it not even if it is fecked? even if i rev it it should get a bit more?

i will charge the battery up and if it starts the car it should charge surely?

i will also go and swap the alternator for one i know definetly works!lol

cheers,
Greg

[greg1.4]

well i have stuck a good battery in it and it fires up no probs.

so i got the voltage from that and it was 12 volts excactly then kept dropping down to 11.90 when i turned it off. it was going down from 12volts when on idle then when revving did not make it charge atall. it should go up above 12 volts, into 13 something volts when revved?? am i right?

so this must mean its the alternator thats nackered?

have i got the wires correct? think there is only 2 (red and blue/white and a big brown earth on bracket), this all i need?

Greg

[Adam]

It should be about 14v when running. Even when idling(it wont change with revs).
Yeah the alt has 3 wires.