Power drain HELP NEEDED!

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 7:18 pm

I have this pain in the ass ongoing problem. I have a .36a power drain and i'm quite confident its with the charging circuit.

Before everyone says "get a new alternator!" its not that. It was doing it with the one i was usign with my sd1 front cover and its doing it with the range rover style one used with my new serp front end.

I've disconnected nearly everything to trying to find the faul but the only thing that makes it go away is removing the centre wire from the alternator.

Also, the charge light bulb is not working. The bulb itself is fine and i've checked the circuitry on the instrument cluster and that too is ok. I've checked for contiuity between the wire for the charge light and the small wire that goes to the alternator and its all good.

Help me.

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 7:21 pm

Forgot to say, with the battery connected and the ignition off the alternator is making a light buzzing noise which is there with the ignition on also.

With the engine running i frequently get a louder high pitched buzzing, it could be a belt noise or the pas pump that i can't get to bleed but i can't help but think its the alternator also.

Post by **katanaman** » Sat May 19, 2007 7:56 pm

u got a half decent multi meter Gav?

Disconnect alternator completely and on the resistance scale put the red on the centre wire connection and black on the body. This should have a very high or infinity reading. If it doesn't you have a problem if it does connect each of the other cables one at a time and check again. If you start to get a reading then you need to check the circuit that wire belongs to.
You haven't connected something to the tacho out connector have you?

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 8:07 pm

Tacho out connector?

Post by **katanaman** » Sat May 19, 2007 9:16 pm

yes one of the connections on the alternator goes to the rev counter (probably via a module cant remember ) on the range rover. Mine does anyway which is a proper inter serps 3.9 alternator and so far as I know they are the same on the 4.0 and 4.6.

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 9:24 pm

Oh right, mine just has 3 poles on it unless theres a connector elsewhere. What does this tacho one look like?

Post by **katanaman** » Sat May 19, 2007 9:30 pm

yes big one for main power a screw one and a spade one cant remember which is which but one is the charge light think its marked D other is tacho think its W

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 9:37 pm

Oopsie. . . . .

My capri's original wiring has 2 thick wires to carry a charge and the rr alternator has (from top to bottom) one big ass pole obviously main charger and two smaller ones. The bottom one i put the charge light wire to and the other two got a thick wire each from the crapi loom.

If i remove the centre wire the drain goes away. If thats the tacho pole then i have the wrong wire going to that.

Could i connect the two capri wires together and put them onto the big pole on the alternator?

Also, still doesn't explain why the charge light doesn't work. Hmmm if i don't set fire to it it may well do that itself!

Post by **katanaman** » Sat May 19, 2007 9:47 pm

Connect all your big wires together you must have had a Lucas alternator before.

Just looked at my wiring diagram which has

B+ main supply big connector
D+ charge light
W rev counter

You will get a drain if you have connected a 12+ to the charge light connector which would also be why the light isn't working.

ihatesissycars · Post by **ihatesissycars** » Sat May 19, 2007 10:07 pm

Looks like i'm leading contender for the knobber award

Thankyou for your help

ihatesissycars · Post by **ihatesissycars** » Sun May 20, 2007 1:40 pm

ITS GONE!!!!!!!!!!

Thanks Marki!

Post by **katanaman** » Sun May 20, 2007 5:52 pm

Glad you got it sorted M8