Confusing altenator problem

Well I got a flat battery recently and the volt meter was running around 9 volts so I baught a new altenator and fitted it. It stayed around 9 volts still.

I have been out and baught a multi meter and tested the battery (also new) and it reads 12 volts when altenator connections are off. When I connect the alternator it still reads 12 volts and the back of the alternator also this normal?

If I dissconnect the wires from the back of the altenator and test just the alternator it reads 0.3 volts is this normal?

This is the second altenator doing the same thing and I took the other one back, surely 2 alternators can't be faulty!

Am I testing this correctly?

Any advice or pointers would be great, thank you. Tom.

removing the connector stops the alternator from working, which is why you dont get a reading. reterminate all your earth cables from engine to chassis

Aaaaa thank you! I'll check that.

What voltage should it read at the battery if it's working ok?

Thank you.

14.4 to 14.8V @2000rpm. all in the CFAQ section

You have to have the drive belt fitted y'knaa....




Sorry!

The Mad Hat Man said:

removing the connector stops the alternator from working, which is why you dont get a reading. reterminate all your earth cables from engine to chassis

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thanks, iv just tried that but sadly it didn't make any difference.

Flossie said:

You have to have the drive belt fitted y'knaa....




Sorry!

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yep drive belts fitted lol.

could it be the wiring? the cables do feel quite old and stiff, could I put my own separate wire in to bypass the old possibly passed its best wiring?

take it to halfrauds to get it tested in situ. or an autoelectrician.

The Mad Hat Man said:

take it to halfrauds to get it tested in situ. or an autoelectrician.

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Cheers mad hat man, last time I went to halfords they struggled to fit a battery! I'd like to do a bit of learning about this too so can help myself in the futre. Iv baught a good multimeter and I can see it's definately not charging.

Could I fit my own loom in to test it's not the wiring?

is the battery warning light going out? is the white energiser wire a good fit on the alternator?

The Mad Hat Man said:

is the battery warning light going out? is the white energiser wire a good fit on the alternator?

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battery warning light doesnt work unfortunately i have 2 thick brown wires and 1 thin brown wire at the top. Here's a pic of the wiring on old alternator....

theres ya problem then. no induction voltage. fix the batt warning light. if yu ground the white wire, does the light come on with ignition?

is the thin brown/yellow wire ,ignition live only

The Mad Hat Man said:

theres ya problem then. no induction voltage. fix the batt warning light. if yu ground the white wire, does the light come on with ignition?

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hi mad hat man, i dont remember the battery warning light working ever to be honest but ill look at sorting that. could it just be the bulb that needs changing?

jamesmartin said:

is the thin brown/yellow wire ,ignition live only

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iv tested it with the multimeter and the small brown/yellow wire isn't getting any voltage at all - with the ignition on or off.

try replacing the bulb first. check there is volts at the bulb with ign on.

toms3 said:

iv tested it with the multimeter and the small brown/yellow wire isn't getting any voltage at all - with the ignition on or off.

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it should to have a live feed from ignition light when ignitions turned on

The Mad Hat Man said:

try replacing the bulb first. check there is volts at the bulb with ign on.

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cheers could i swap a bulb to test it with another out of one of the other dash clocks? until a new one arrives.

no more than 5w.

jamesmartin said:

it should to have a live feed from ignition light when ignitions turned on

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just to be sure i tested the right one you do mean the smaller wire with the bit of red tape on? would it be worth looking at the back of the ignition switch to see if one of the wires has disconnected?