battery flat again

[swedge]

this is the third alternator ive put in and my battery keeps going flat

the second time it was the battery that was gone but i had already changed the alternator anyway

so its had 3 alterntors and a new battery

ive un hooked all my amps etc thinking they could be using too much power in this cold weather and the alternator couldnt keep up but its obviously not that

they werent new alterntors i used as replacements so dunno how old they are

is it time to buy a new one and not second hand?

[swedge]

also will any 8v corsa/nova alternator fit my c14se?

will a diesel one be any better?

[C612DNM]

Before you throw another one at it, check the current drain of it with everything turned off. For that you need a proper multi-meter (standard 10A type will do, not a 50p off the market job).

Something is draining the battery, or on the other hand, your battery isn't being charged properly. While the light may be out, there is still a good chance that you have high impedance earthing which reduces charge voltage and current. The earth strap from the alternator to the block, and the gearbox to the chassis are often tired, as is the one from the battery to the chassis.

Something I've seen people do on here which won't help earthing is paint their gearboxes - which puts a degree of insulation in the earth path from the alternator to the chassis. If you want it to look clean and shiny, get it blasted, and make sure that the mounting surfaces of it, and the block are clean of paint and debris, and that the bolts are clean too.

Start with the basics, and you'll be surprised how simple problems like this can be solved.

[swedge]

the earth strap on the gearbox and the battery are both fine

the earth strap from the alternator to the block is that just the black piece of bar that bolts to the top of the alternator then to the block?

[General Lee]

nope it's the braided type earth strap! iirc

[mowgli]

old school method. disconnect the +ve battery wire. put an ammeter on the +ve battery terminal to the +ve wire, then with the ignition off, start removing fuses one at a time till the current draw stops

[swedge]

Think I've found my problem all along

There's no strap on the alternator

I've made up a cable at work with 2 connectors on the end

Where do the ends bolt to?

Would it be ok to bolt it from the mounting bracket hole on the passenger side of the alternator to the block?

[swedge]

well fitted the cable to my alternator and bolted it to the block and it runs perfect

i turned on everything like lights heaters etc plus my 2 amps and it still sat at 14v

cheers guys