Thread: One more problem - Help Needed

diode pack in the alternator is starting to fail. or the regulator is doing the same. If your really lucky its the contactrs on the slip ring

your tacho runs off the


dead or dying ALTERNATOR



Is it full of mud by any chance?

Originally Posted by wrex

Hi all,

My V8 Disco 1 is playing up again.
Symptoms:

This morning, there was a faint bearing type noise that I had not noticed before.

I later found out that by turning the radio off, the sound would slightly disappear.

I went for a drive this evening and now the battery light is on on the dash and my tacho is not working.

With my limited knowledge, I know the battery light normally means the alternator is not charging however I’m not sure why the tacho stopped???

Any suggestions as to what the problem could be?


Thanks,

Carlos

Im guessing it,s the alternator as the tacho is driven off the alt

I wish it was mud, it would mean I've been doing what I bought to do... but all it does is break down every 6 weeks...

Oh well, I still like my Disco..

Ok, so two questions now.

Since all wires seem to be clean and tight, can I use the multimeter to test it and how much current should it be putting out?

Dave: The diode pack and the regulator are they part of the alternator and if they are the ones playing up, should i just source a replacement alternator???

put your mulitmeter on AC and measure from the main battery out terminal (you should be able to get a probe in there) and the chassis of the altenator (main body) old school alternators had an allowable limit of about .5v but you could push it to 1 or 2 v before charging was seriously effected.

With the new electronic injections and the like the voltage ripple is enough to cause problems with other things and the max tolerance is lower and 0 is obviously best. I'll have to consult my books to get the exact acceptable ac voltage.

Given the time constraints were going to be under on saturday morning we might be able to sneak a new alternator in but we wont have time to dissect yours. Id go a new one before something else goes wrong. In the mean time if the alternator charge light is staying on you need to keep the battery charger hooked up over night to keep the battery charged.