Is my alternator gubbed then?

[Donald360]

The van has only been run occasionally over the winter (couple of times a week). I noticed a few days ago however that the leisure battery appeared to be completely flat and was not getting charged whilst driving. Road battery seemed ok. Checked the charge coming from the alternator and it was about 13.5 volts, this is much the same at the alternator terminal to earth and across the batteries when the engine is running (the same for both batteries so I reckon the split charge relay is working ok as well). I forked out £12 for a new voltage regulator for the back of the alternator as the old one had very little of the carbon brushes left, but no difference when checking output.

I'm thinking that the alternator itself is goosed. The question now is what to replace it with and who is the best stockist? The van is a 1985 1.9 DG. I'm also concerned that something might be draining down the leisure battery

Cheers
Donald

[Oldiebut goodie]

Most of us are using 14.5v regulators when we replace them - what voltage one did you put on?
Have you checked all terminals for corrosion? What earth did you check it with - are all earth connections clean and tight especially the gearbox nose one as this gets all the crud from the road?
The alternator is unlikely to put out 13.5v if it has gone West. What amps is it putting out?

[ghost123uk]

And try measuring the voltage with the leisure battery disconnected (make sure you safely insulate the +ve feed wire you just took off the leisure battery). If the leisure has been left flat, it is 99% certainly gubbed and may be dragging the whole system down. Though a dead battery normally has a high internal resistance, but it's dead anyway, so try it.

Take care if doing as OBG suggests by measuring the amps from the alternator. Most multimeters (and their leads) are not man enough to do this and will burn out

[Oldiebut goodie]

I tend to forget that people don't have access to tools. My clamp on ammeter is good for 500 amps!

[ghost123uk]

I tend to forget that people don't have access to tools. My clamp on ammeter is good for 500 amps!

[Donald360]

I got a new 14.5v regulator, but after fitting it there was no difference - still about 13.5v. I have been measuring the voltage from the larger nut at the back of the alternator and eathing it to the engine, which has a nice new earth strap so should be good. The alternator, if not original, is certainly a good number of years old.

I am wondering if the split relay might be acting up and have an intermittant fault, ie only switching occasionaly, or is it the kind of thing that either works or doesn't.

Not wanting to fork out £100 for a new alternator if I don't have to, so appreciating the feedback. I will try testing it with the leisure battery disconnected and see if there is any difference.

Cheers
Donald

[jamesc76]

disconnect the alternator start the van (insulate very well terminals removed and then measure the voltage at the alternator, if a batter is goossed it will drag the volts down!