Alternator not charging! Whats changed?

[christhemann]

Was feeling pretty pleased with myself having replaced the water pump, thermostat and flushed the cooling system over the weekend!
Temperatures seem much better and no noise from the pump.
However, yesterday the battery failed and needed charging before I could start the car. I put this down initially to having started it several times at the weekend to circulate the water, but now having tested it with a multimeter the voltage is 12v before and during running!
Also the battery light never comes on, even before the engine starts as before.

I did have to remove the alternator to do the water pump, and have since cleaned and checked all the terminals are ok.
I broke the blue wire though and had to crimp a new connector on, it seems a good connection now.

Any ideas what could have changed? Anybody else removed the alternator only to find when fitting again it doesn't work?
I've even changed the brushes twice, no difference.

Thanks in advance.

[ianaudia4]

Check the earth mate.
I did my new water pump at the weekend, runs like a dream now, along with new plugs, new leads, oil change...................................................................................and still things to do!!!!!

[christhemann]

Good to hear you got yours done well!

By the earth, I take it you mean the main earth strap to the gear box mount by the battery?
Will check again, but I believe i've checked this already.

Have tested alternator with +ve connection to the outer casing as -ve. Same voltage as directly over the battery.

[PeteGLi]

Double check the blue wire.

[Nate]

Double check the blue wire.

2nded. this will be your problem. it "excites" the alternator and makes it work. it connects thru the warning light on the dash to battery +ve, via the ign switch

[christhemann]

An update!

As quite rightly mentioned, I checked and double checked the blue wire last night.
I did the test which was recommended by grounding the blue wire and seeing if the light ignites on the dash which it does!

I also ran another wire straight from the +ve on battery to the blue wire terminal on the alt. and nothing, still no voltage. (about 11.5)

So went out and bought another alternator today, only a 65amp not the current 90 but hopefully be fine.
Hope it WAS this, will find out tonight.

Thanks a lot.