The Classic Machinery Network

Hello All,
A Ford4600 has an alternator fitted.
When you have the tractor running the dashlight for the alternator goes out ok, but the output voltage only rises to 12.70 volts, even at fairly high revs.
Is this as good as it gets I wonder, or should I have the alternator checked on a bench.
Regards and Thanks to all. 15-5-2017

Hi Pat and welcome to CMN sounds like you have a problem there as the output from the alternator should be around the 14.2 to 14.5 volts, what state is the battery in before you go looking at the alternator, does it hold a good 12.5 to 12.7 volts okay?

Jeremy

Welcome Pat sounds like the brushes are badly worn on the alternator
What you describe is a very common result as the brushes no longer make a good connection to the slip rings

Paul

Hi Pat, welcome along.
Do you know if it's it the original alternator? Some after-market types will fit but the pulleys are sized for a petrol engine running at higher revs so your Ford wouldn't really be spinning it fast enough.

Jeremy Rowland wrote:Hi Pat and welcome to CMN sounds like you have a problem there as the output from the alternator should be around the 14.2 to 14.5 volts, what state is the battery in before you go looking at the alternator, does it hold a good 12.5 to 12.7 volts okay?

Jeremy

Hello Jeremy, thanks for your support, The alternator is a new store bought one , I'll make sure the Batt is in top form and then check the Alt. Output Volts again. Another kind responder suspected the pulley size might be in question.!!
Thanks to the other lad also but as the Alt. is new I.d say the brushes are unlikely to be bad.
Thanks again all,
Regards Pat.

Was the previous unit completely stuffed or did it have a similar issue? It's also worth bearing in mind that it is unlikely, but not impossible for a new unit to be faulty.
Let us know how you progress, and it doesn't matter if it's a working machine or a restoration project some pics of the beastie are always appreciated.
Rob.

check conections and the regulator may be crook
I am assuming its a solid state regulator ?????


Paul

if you take a photo of the regulator and the alternator we should be able to tell you were to test and what to test

Paul

be aware that the Fords had an alternator cut-out built in the bottom of the battery tray, it sensed when the battery was getting warm and shut down the charging. Just be sure its not failed.