Outer Limits 4x4 Board

I have a GQ TD42 with a new alternator, i replaced this at xmas time when i filled the old one with mud and it refused to work after much cleaning etc. Was unable to strip the old one done as the casing has welded itself to the bearings. The new alternatori bought is only charging at 13.1 on rare occasions and most of the time sits at 12.6. Have used 2 digital multimeters at the batteries and at the alternator output but still stays the same.

Is this bad for the batteries or am i better of getting it looked at or replaced etc

Double check the wiring.

Should charge at around 13.8 once you bring the revs up. Can be less at idle but under 12 isnt very good. If it isnt charging at or near 13.8 then I would take it back and get them to test it and replace if necessary.

Im assuming you mean the alternator is NEW NEW and not "new second hand"?

It won't necessarily be bad for the batteries unless it isnt charging enough and starts to discharge the batteries when youre driving at night with all the driving lights, tv, fridge etc on in the car.

nope brand new $450 worth of new. At idle its more like 11.4v i have checked all wiring and tested at red output wire on back of alternator as well

id go back n see em
i paid alot less than that for a new 70A one with a vac pump here is bris
search for the details if your keen

Before you take it back, check voltage with your multimeter at the alternator instead of the batteries. Earth your negative and probe the power terminal on the back of the alternator (where the battery lead attaches)with the positive. If you're getting 13.8 or more then you have a problem between the alt and battery.