[g4vvq1983]

Hi Andy, strange one, i'm not 100% how that Alternator is wired, but here are a few pointers, do you have a Multi meter or voltmeter, if so put it on say a 20 volt scale and put it across the battery, without the engine running it should be minimum of 14.4 volts, with the engine is running it should be 13.9 to 14.7, that will tell you if its charging or not, Now i think your alternator has probably got 3 wires on, the big thick one goes straight to the battery positive terminal, make sure it's live all the time, there is prob a wire for the rev counter, goes from about 1 to 5 volts running, and there is a wire for the warning light, now the warning light wire normally either goes to the warning light bulb, or to a relay which turns the warning light off, usually under dash..the warning light wire on the alternator should have 12 to 14 volts on it running and 0 stationary, Make sure if the alternator is rubber mounted that it has a good earth on it, some of the vauxhalls have rubber mountings, and a big black earth wire, sometimes dont connect very well,..i suspect the fact the light comes on then goes of quick is a bulb or system test when you initially turn on...hope that is helpful....from Fred in Essex.

 

[g4vvq1983]

Hi Andy, yes sounds like a good idea, yep the Vacuum pump is because it is a diesel, and a diesel has little or no Vacuum in the inlet manifold to work the brake servo, or as the Americans call them, Brake booster...you can actually buy it without the pump from a factors and swop them over, cheaper that way...Fred in sunny Essex, at times, mostly raining.

 

[g4vvq1983]

Ok Andy it's still a bit low, one thing i should say, when the battery is down the alternator should throw a ton of current into it, at that point the voltage will be low, your supposed to check with amp meter on the battery lead as well, but i was assuming you don't have an amp meter, if not you have to have the battery voltage at least 12.4 volts to start with to get an accurate reading when it's running, you will need revs at least 2000 rpm to get charging reading right, 13.9 to 14.3, it sounds like its charging a bit but either not enough or intermittently...i do know with older systems the ignition warning light has to work or it wont charge, make sure the fans belts tight, ....sounds like your weather is worse than ours, i just has some turf put down in the garden and haven't had to water it yet..brilliant lol.

 

[g4vvq1983]

Hi Andy i was having a look at the charging system on a wiring diagram last night, on my car there appears to be 2 wires, one goes straight to the battery, thick red one, and a blue and white for the warning light, goes from the alternator to the Multifuntion Module, fron there it goes to dash light etc, so it's not a straight forward circuit, but i would stick to basics if you can...Fred.

 

[g4vvq1983]

Hi Andy. on the first message above it should read when the engine is stationary the battery should read a minimum of 12.4 not 14.4 too may late nights....Fred.