Electrical discharge

[lewton]

Hoping someone can help.
Battery went dead in my 93 precat Griff.Because it hasn't been used much recently assumed that the battery was shot so put in a new one.Jumped into the car yesterday fuel pump primed and then nothing.Got the car started with jump leads and put a test on the alternator which was showing a charge of around 14 volts so all appears to be well there.Only thing that I can think of is that there must be a major power discharge somewhere.Anyone got any ideas?

[steve-V8s]

Prime suspect has to be the pin switch below the door that is for the internal lights. There is a plastic button attached to the door that presses the switch when closed, when the button falls off the lights stay on with the door closed (even if they are switched off at the light fitting the relay will still flatten the battery) The other favourite although probably not on your car is the passenger foot well light, easy to switch on accidentally and not notice it.

[Hoover.]

if it aint the door switch, try the interior light dealy relay (yellow)...... I ended up getting an auto electrician to mine (didn't tell him it was TVR... which apparently if he had known he would have declined )... as soon as he saw the relay he said that he suspected that to be root of my issues with out doing any tests..... and he was right, apparently known to fail regularly on fords which it is from.

[Al 450]

Could be the dodgy alarm or a short to ground somewhere. If you can't find it then measure your current drain with a multimeter and then just pull fuses out one by one until the drain drops. You will have narrowed it down then.

If your battery is going flat that quickly then chances are it'll be a drain of a few hundred milliamps.

[Loubaruch]

Could be something draining current away but when you checked the alternator did you just check its terminals? Did you check that the dynamo leads are actually conducting current. The alternator connections are known to be a problem if dirty, well worth taking them off and cleaning in any case. You can tell if the alternator is actually charging your battery by viewing the voltmeter reading while driving, anything less than 13 volts suggests a problem.

Forgot to mention if you do clean the terminals ensure you disconnect the battery first or you could have a few sparks!

Edited by Loubaruch on Thursday 2nd July 22:08