Charging issues 4jg2 Bighorn

[samk115]

Went for a bit of an explore on a new track today. Great time, but it appears my charging system has decided to call it quits.

There was a lot of mud and water, are Bighorn alternators particulary susceptible/known for failing in these conditions? (When i say a lot i mean A LOT)

The charging system light is proofing out, but i am getting no charge to the battery. I have removed and manually tested the operation of the Charge relay, seems Fine. I find it odd that i am getting no charge yet the light is going out, is this a known issue?

Im thinking its going to be an alternator fault, im thinking about pulling it off and having it tested at a local sparkys however it looks like a bit of a prick to get off so any random things to check before i carry on would be great!. I have also found an alternator cheap locally so will probably pick that up just in case.

[geeves]

2 things happen to bighorn alternators
If your lucky its filled up with mud and the brushes have stuck. If not its burnt out the stator but that normally kills the charge relay as well. Both are alternator out jobs.
2 ways to get it out
popular way
battery out belts off
Aircon bracket unboted from block and placed on battery tray alternator out. Easy takes a bit over an hour
Way championed by a member here who is an isuzu mechanic
Bat and bolts out
radiator out
alternator out. I havnt tried this way but when I took the radiator out to do the steering box I wore half the coolant in my face

[samk115]

Cheers for the reply.

I see on trademe there is exchange alternators available cheap, but they are 60amps.

Has anyone swapped the 80 down to a 60 here?

[geeves]

Mines a 60 If it ever needs replacing though I will be getting the biggest I can as I have a winch etc

[samk115]

I pulled it out last night, turns out someone has fitted a 50A unit to the truck!

Ill strip and test it today, if faulty i will probably try one of those refurbished 60A units.

[samk115]

Pulled it apart today, found the oil seal on front of the vacuum pump had failed, letting oil seep into the guts of the unit. Slip rings were coated in oil. Cleaned them up but out test bench at work was having a hissy fit so unable to test for output today. Slip rings didnt look to be very healthy so may have further issues but want to test it for output now that i have cleaned the oil off before i take any further steps.

Seems like a fairly nasty coincidence at this stage, although water/dirt could have caused pre-mature failure of the seal i guess!

EDIT: To confirm, It was definitly the oil ingress that caused my issues, its running sweet as a sweet thing now. I did notice quite a lot of scoring from the old seal on the vacuum pump driveshaft that if not tidied up would have caused a leak with the new seal so that will be something to watch out for if anyone else has similar issues!!