Thread: Cranking and Aux Batteries dropping down to 50% charge: Traxide isolating

Originally Posted by BSM

I have been doing a bit of under the bonnet electrical detective work using this excellent how-to from the UK Disco4 site..

I purchased a cheapish Amp Clamp on-line to do this which as it turns out probably wasn't the best one I could have bought for this purpose because the jaws are hard to get into some places, and they won't open large enough to fit the huge starter motor cable, but nevertheless, I have got some useful readings.

I am seeing a quiescent current draw of about 88mA through the main cable from the battery to the junction box, which is four times recommended draw. Investigating the voltage drop across the fuses, I am seeing pretty much nothing on all of the fuses except for a reading across F26 of about 8OmA. This is the fuse to the suspension ECU.

Additionally I was reading 100mA through a straggly wire that comes out of the junction box, and dissapears into some flexible conduit and goes goodnes knows where.

I need to repeat my measurements, and hunt to down where this straggly wire goes because I ran out of daylight yesterday.

You can see the straggly wires I'm talking about hanging out from the battery box at the bottom of the attached image. Any idea what it might go to?

Incidently, can anyone tell me what the small black box is that is mounted in the engine bay directly aft of the washer bottle in that image? It has an integrated fuse, and the cables dissapear down the engine bay and I think go under the vehicle.

Driving lights, old dual battery system, if you bought the car second hand, they may have removed something when selling the car, could be something for towing, towing a trailer with LED lights, hands free kit, those scraggly wire are a fuse going back into where the main battery is, see where they go.

As for the black box, follow the wires from the black box, gotta lead to somewhere.

Baz.

The little black box looks like something you'd buy from Jaycar, probably a home made magic rust zapper, about as useful as mammaries on a male bovine. Pull the fuse, your car won't stop running.