Club 80-90 Forums

hi im now starting to despair, my 1.9 dg isn't charging, I have replaced the battery with a new extra heavy duty, buy shows 12.35 when engine is off when revved it stays around the same , I tested my meter on another car and that's fine , I replace the brush pack I, without any change and now I have put a new bosh in and still the same any ideas would be great cheers

Have you checked the cables running from the alternator to the battery?
Have you measured the voltage at the alternator (keep the cable attached)?

hi , where do I check the voltage at the alternator would that be the bigger of the two terminals, I have three wires running to the bigger terminal with a nut and then one running to the smaller one with a nut, does the battery cable the thick one run direct to the starter then the alternator or is the thinner wire on the pos terminal the charging circuit thanks for getting back

I don't have that style of alternator (mine has a connector) but you're looking for the one with think cable(s) going to it; connect the positive probe of your meter to one of those (while it's still connected to the alternator) and connected the negative probe of your meter to a ground (i.e. the engine block) and measure the voltage (with the engine running).

FYI #1 The thinner wire will be the exciter wire - it provides 12v to the alternator at start-up (it's also the wire that provides the signal to the battery light in your dash) - which begs the question: Does the battery light go out on your dash after the engine starts?

FYI#2 The charging circuit runs from the battery to the starter (the really thick cable), then from the starter to the alternator (a less thick wire or possibly two wires).

ok thanks I will check, I only have 3 thin ish wires to the bigger of the 2 teminals, that's the strange thing the alt light goes out, on saying that I will check that tomorrow I need to make sure that its coming on in the 1st place

Well - the battery light going out (assuming that it does come on first!) pretty much confirms that the alternator is working but not that the alternator output is connected to the battery!!

ive just checked and the little battery light next to the oil light comes on and goes out when the van is running, is that a cable fault then anyone know what one im looking for

Well - at least that proves that the alternator is producing voltage - you just need to figure out now how much voltage it is producing and if any of it is getting to the battery.

A pic might help of the alternator wiring as that seems like quite a lot of wires going to the alternator (I thought that there was usually either one or two wires for charging)

earlier it was showing about 12.35 when off and then the same running and revving the only difference was the meter when running was show 12.35 12,50,12.10 and seemed to stay around those numbers sometimes hitting 11.75 im baffled

I will post a pic tomorrow I thing the previous owner has been messing around as there seems to be wires everwhere

So...placing the positive probe of the voltmeter on the 8mm stud (13mm nut) rear of the alternator and the negative probe to a good earth.....you get anything ranging from 11.75 - 12.50 volts? and there is a good engine earth (if not know then use a jump lead somewhere on the engine to a bar bolt on the chassis)

Martin

will do I will take a look tomorrow, the reading from the alternator stud 11.75 plus would that be classed as normal or should it be higher thanks for all your help

Do you have a leisure battery and split charger?
If you do is the leisure battery connected and fully charged?

If the leisure battery is very low I think it could be taking most of the output of the alternator!

Just a thought, I think thats how a split charge system works, but I may be wrong. If the you have a leisure battery and split charge you could try disconnecting the leisure battery and measure the charge rate of the starter battery again. The starter battery should be receiving more than 12.5 volts, I thought it should be somewhere near 13.5v to 14.5v normally.

no les battery the butcher who had the van before seems to have messed with the wiring, on the right hand side od the engine bay fixed to the side is a small relay I havnt a clue what that is I will take some pix tomorrow and post them cheers