Alternator woes

[Silverfang]

After having had a charging issue on the car a few months back, which was traced to a blown alternator, I replaced it, then again, to have more woes as it turned out the new one was faulty.

And today, I've checked the charging rate on the 3rd one after I'd accidentally left the lights on, managed to drive the car back from Lemington Spa last Thursday (about 50 miles ) and a round trip today (150 miles) and found that the voltage is only about 12.30 volts according to my volt meter, whilst the engine runs

I don't want to have to fork out for alternator number 4 but is there any reason WHY it wouldn't be charging very well or at all???

[Grrrmachine]

Could be something as simple as a corroded engine-to-body strap causing increased resistance, or similar corrosion around the starter terminals. That presumes all your battery connections are bolted on cleanly and tightly, of course.

Is there any chance you've buckled the pulley somehow, or your alternator belt is in the wrong groove of the crank pulley (some cars have three down there, for P/S and aircon).

[Silverfang]

And nevermind! Friend tipped me off about running a jump lead from the negative on the battery to the engine block... low and behold, 13.5v sprung up... DAMNED EARTH LEADS



Now to get ahold of some replacements.

[Brianmoooore]

I posted on this last week in another thread. Many perfectly good alternators are replaced at considerable expense, when all that is wrong is a bit of corrosion in their earth path to the engine block!

[Silverfang]

I will have my alternator out tomorrow Brian and give the mounts a F'ing GOOD clean up with a wire brush and add in another earth lead to the block direct (Did this on a previous E30 and It REALLY does make a difference)

[Silverfang]

Earth leads were checked today, no problems there, resistance check and condition generally good.

However the lower mount for the alternator was grubby as anything, a good blat with a wire brush and reinstalled the alternator, low and behold we have a solid 13.8v showing on the meter

Best kind of fix is a £0 spent fix. All that though was frustrating.