Lack of battery charging

[old-git]

I have a lack of battery charging on my Ford Sierra Cosworth. With the engine off volt meter says around 11.8volts. Engine running it is slightly less when it should be 13-14volts. Tried 2 spare s/h alternators but get the same readings. No battery light on dash. Lead from alternator to battery is fine with no resistantance, according to the ohm meter.

Help! Any ideas before I buy a new alternator?

 

[obi_waynne]

Do you get a reading across the alternator terminals with the engine running? Disconnect and reconnect all battery and earth points. It almost seems that the power from the alternator is going missing somewhere.

Does the voltage regulator sit on the alternator or is it a separate unit? Can you charge a second battery from the running engine with a direct connection to the alternator?

 

[HDi fun]

Is it just that the battery is knackered and not holding charge?

 

[old-git]

Thanks guys for the suggestions. Problem has been found, it was the battery light on the dash! This had blown so no signal was getting to the alternator telling it to charge! New bulb fitted and battery now charging at 13.8ish.

 

[obi_waynne]

Wow - talk about obscure? Glad you found it though.

 

[jarrus]

Seriously? because the battery light had gone the whole charging circuit stops working?

That's bad....

 

[old-git]

Yup. Obviously not uncommon as the garage were aware of it. Modern car charging is usually done via the ECU but with the Sapphire we are talking about the dark ages