Alternator woes

[Jonthefish]

3l diesel Surf gen 2.

Loss of electrics last night (numerous warning lights, dimming headlights). Made it home and re-charged batteries overnight. I've now replaced, started and tested alternator. No charge is getting to batteries on fast idle so definitely not getting power up from the alternator. Belts are all good.

I disconnected both battery negatives and put an ohm meter between the charge cable at the alternator post and the battery positive. I'm getting a reading of 0.2 to 0.3 ohms between alternator and battery.

I'm a bit thick with electrics (as with many things) but from what I've read the reading suggests 100A fuse is is ok and that in all likelihood the alternator is a gonner.

Would that be right?

Thanks.

[Jonthefish]

After some investigations and cleaning of battery terminals the alternator briefly started putting out 14.6 volts. Thinking all was well i went for a run with lights on. After a couple of miles got the warning lights. Went home and put a meter across it. Max output 13V but going up and down and sometimes not charging.

Puzzling.

Took it to local garage and they reckon alternator has badly worn slip shaft and brushes causing bad charging, especially under load. Alternator getting hot. So, new alternator ordered. Will update if that sorts it.

[Diezel Weazel]

Hi Jon sorry to hear of ya woes Bud.
I normally get the Alternator, Starter checked by a Lucas auto electrician first n
if a simple fix get em to do a refurb at the same time..
By the way output should be between 13.8 n 14.2.
Good Luck

16+ Years of Surfs .. n Faultless to a "T" is my Yota !! Now I have 2 Surfs again

[Jonthefish]

Cheers DW. I'll update once the new alternator is in. Fingers crossed the idiot couriers will get it here (west Highlands) before all the Christmas malarkey kicks off.

[Jonthefish]

Alternator fitted and charging at a steady 14V. Phew.

Then realised MOT was due. Truck sailed through for the second year in a row. Nice one.