Alternator wiring/ charge warning

[tomwood_uk]

Hi guys,

Having trouble with my alternator after refitting my rebuilt engine. Basically I'm getting no charge to the battery, but 13.8 volts on the positive terminal of my alternator. Also getting 12v to the blue exciter wire. However, with ignition on and engine not running there is no charge warning light on the dash. As i didn't have any issues before removing the engine theres a good chance I've wired it up wrong somewhere.Any advice?

Cheers

[irishs2]

This is the wiring on my alternator (ABY avant)

[quattro-nick]

if you disconnect the blue wire and you hold it to a groundpoint somewhere on chassis or engine the charge warning light on the dash must burn
if this is so, the alternator will be broke

[tomwood_uk]

OK I'll check that now. If the light does come on could this be a bad alternator earth as it had been painted ?

[Error404]

The alternator earths through it's body so yes make sure its getting a good earth to the engine

[tomwood_uk]

Cheers gents. Earthed the blue wire and sure enough the light illuminates. Think ill pull the alterantor back off to check the earth path.

[Bowie69]

And check you refitted earth strap to engine.

[tomwood_uk]

And check you refitted earth strap to engine.

I did, fitted a new one actually. Just had the alternator and mount off, cleaned up all mating surfaces, refitted and checked. Still no charge warning light at ign on. With the engine running I'm getting a pretty constant 13.8V at the alternator pos, and 13.5 and the battery (under rear seats). It took a few seconds after start-up before any charge began to show.

When the engine gets warm and the fan kicks in, the idle becomes very rough and the charge voltage does not change from 13.8. Think I'm going to take it to be refurbed in the morning, can anyone tell me the bosch model number for a '93 aby coupe? Cant make it out on the sticker.