No charge light while engine stopped or running. And no charging!

[AlleyNiki]

Hi everyone and thankyou all for helping me in the past.

Once again I pester you in the small hours for my beasty (1989 a/c, 650cc. Colour: RED) is having another of those days! 

The problem is that the battery is not charging while the engine is running, and the 'not charging' light never comes on, whether the engine is running or not. 

This had happened once before when one of those wires with the crappy spade terminals in the plastic square sheathing on the alternator decided to just slip off. Putting it back on fixed that problem. 

But this time none of the wires (that I can see anyway) have fallen off the alternator. I've also tried  pulling one off (black lead, spade clip goes on vertical like an 'I') and found that when touching the alternator casing -which is earth I guess - the not charging light would come on. 

I'm pretty certain the belt / pulley is turning the alternator - I'll check that again.. Not that it would be affecting the light.

I've scoured the forum for an hour already and can't find anyone with the same problem..   
Any clues, people? 

Regards

Alastair

[AlleyNiki]

Yes, the pulley and belt are all fine. The alternator spins. Nothing over tightened..

Could this be an alternator brushes problem?

Alastair

[Pete126]

On some fiat models if the charge light has blown there will be no charge coming out of the alternator, so check that first, the bulb is used in the circuit to excite the coils.

Here's a video that explains how the alternator works.

[youtube]http://www.youtube.com/watch?v=EqdrkZu50Vw[/youtube]

[AlleyNiki]

On some fiat models if the charge light has blown there will be no charge coming out of the alternator, so check that first, the bulb is used in the circuit to excite the coils.

The charge light hasn't blown. It came on when I accidentally let the black wire which goes to the brushes touch the outer casing of the alternator. (After disconnecting this wire of course to check the contacts)

 

[AlleyNiki]

Terrific video by the way! That really helped me to understand what alternator does and how it works! That guy should be a lecturer at a uni. 

Cheers!

Alastair

[AlleyNiki]

I took the brushes fitting out last night and cleaned it. Tested it on a multimeter to see if current flowed through and it's fine. 

The regulator may be suspect though. 

Can anyone tell me which wire coming out of it fires up the electromagnet? Is it the green one that plugs into the topmost contact on the brush fitting?

Thanks people,

Alastair

[AlleyNiki]

Dunno if anyone's reading this but today I sourced the problem:

I stuck 12v through the rotor coil straight from the battery and spun the alternator up after disconnecting the wires.

Presto! I get 19 volts coming off the windings.

It's the regulator. I cleaned up the regulator contacts and it still made no difference, so I'm ordering a new one.. Pity the Elmot regulators don't have the mounting brackets in the same position as mine.

Must remember to order a new oil sensor with the regulator..