alternator not working

[plumAJP]

right it did work before i pulled the engine out.

either i have wired it up wrong or
when i painted it and cleaned it i broke something.or painted something wrong.

i have had a multi meter on the battery and had the car evving on 2500rpm and voltage was 10.5v
3 questions :

1. what are the alternators off?

2. how many wires connect to alternator? i have 2 only (thick red and skinny earth with spade connector on the end that slides over a male spade which is houses in a grey plug coming off the loom.)

3. if i give it to a refurb place near me will they be able to get new brushes etc or are they wierd non generic bits inside that a generic alternator and starter motor garage wouldnt have?

[VPower]

Did you check the voltage at the alternator end?
Just in case the big fuse has gone?

Have you checked the earth strap from the engine to the battery/chassis?

Steve

[plumAJP]

i have an earth from the block to the chassis, and then one from the battery to the chassis.

im goign to check the out put from the alternator today.

does somebody know where the wires connecting to the alternantor come from/ go to?

positive red wire (thick wire)
thin black wire
any others im mising?

[fatjon]

You seem to be missing one. According to the wiring diagram the wire to the dashboard alternator light is a 0.5mm brown/yellow. Without this their is no field supply to kick the alternator off.

[plumAJP]

checked voltage direct fro terminals on alt, while the wires were still attached.

it read minus 2.5v fluctuating on idle, when revved it went to +0.5v.

definetley only2 wires on my alt. one black wire with the yellow tag with alternator written on it.

and thick red one that goes to the big fuse and then into the starter motor.

there is a male spade termial protruding from the alternator but i have nothing to fix to it.


however after its first run and proper blast at roughly above 3.5k the light went out and stayed out for the trip even on idle.

after a stop and ten min break i started her up again and the light was back on. after a big rev above 4k ish the light went out again.

[FarmyardPants]

A poor connection with the big fuse maybe? The big fuse is on the charging circuit. With no big fuse the car will run but battery light on dash will come on and batt won't charge. May be worth removal/cleanup/refit.

[fatjon]

if the alternator light works you don't have a wire missing, looks like the manual may be out of date. Big fuse does cause an alternator light flicker when it's about to fall apart.

[plumAJP]

its a brand new 100amp midi fuse and i sanded the connections on the wires before i installed it.

i have checked it and the fuse has not blown.

i may remove it after mot and clean it up again and make sure the connections are spotless, but im prety sure the connections are good now.

[VPower]

plumAJP said:

checked voltage direct fro terminals on alt, while the wires were still attached.

it read minus 2.5v fluctuating on idle, when revved it went to +0.5v.

definetley only2 wires on my alt. one black wire with the yellow tag with alternator written on it.

and thick red one that goes to the big fuse and then into the starter motor.

there is a male spade termial protruding from the alternator but i have nothing to fix to it.


however after its first run and proper blast at roughly above 3.5k the light went out and stayed out for the trip even on idle.

after a stop and ten min break i started her up again and the light was back on. after a big rev above 4k ish the light went out again.

The big red one should read battery voltage when connected to earth via your test meter! As it should go to the battery positive side.
So there is a break between this and the battery if that is how you are testing it.
Bypass that new fuse, as it could be a duff one.

ETA - check the resitance of the earth from engine to battery negative with your test meter. Should be very low resistance.

Edited by VPower on Friday 14th August 22:21