Just about to have a bloody bonfire!!!

[GQPorkroll]

Seriously pissed off with this thing now. Long story, ill start at the start.

Bought the truck with a dual battery setup. Aux side was shit so I replaced it with a deep cycle battery, shortly after the start side battery stuffed up so I put a new heavy duty battery there. (12mo ago +-)

Everything went good for a few months then it was slow to start. Checked battery and got it replaced under warranty, I used the Century battery in my soarer and put a Alco battery in the troll on the start side. Thought that was the end of it, but still had slow starting dramas. Changed starter. Everything was fine.

Truck was laid up for about a week or 2, battery was absolutely dead flat. Jump started it off the aux battery and it ran fine. Drove it about 50km and next morning it wouldn't start again. Jump started it and drove to work, then went for another drive, probably 50-60km, next morning, dead again.

Ordered a new alternator and sat it in the back yard for 3 weeks or so, fired straight up and I thought it was going to be ok, but after using it for a few days, the battery was always dead in the morning, but the aux battery would always jump start it. The volt gauge was showing around 13ish volts in the cab on the gauge.

Changed the alternator today, shit got worse. Main battery isn't getting any charge at all. I put my multimeter across the battery and it was draining with the truck on, the block behind it that is for the dual battery set up showed 11v on one and 9v on the other. Couldn't access the alternator to get an accurate reading, however it's all the same, I put a new terminal on the positive lead as this alternator has a bigger bolt, and I had to reposition the earth lead to another place on the alternator. The plug to the regulator is connected securely and all bolts for battery wire and earth are tight.

Almost everything is running off the aux battery (fridge, cb, sub, HID's, etc) and only the original electrics and a camera in the cig plug is running off the main battery. Nothing is running when the truck is off to drain the battery. All terminals are tight and in good condition.

I noticed that when I changed the alternator, the battery gauge stays on as do the red lights, this never happened before. I disconnected the relay for ignition and they go out, but changing the relay didn't help, they still stay on when I turn the key off. I'm just disconnecting the battery now.

A few things: my key is loose, but it turns the truck off and all functions on the barrel work. I am sus on my battery, ever since I've fitted it, I had a feeling it was faulty and regularly throw a charger on it to make sure it will start. The dual battery system is a fair few years old, and it seemed a bush mechanic owned the truck before me as I've encountered a lot of dodgy things since I've had it.

So, in my mind, I have 2 problems. The alternator isn't working, so it's either faulty from new (unlikely but possible) or it's due to me repositioning the earth lead. Also, my battery isn't charging properly. I suspect that the dual battery system is faulty.

No idea why my dash is staying activated when switched off. I don't mind changing my barrel, as my passengers door lock is stuffed and I will also replace my rear door if I get a complete set, but I think it's more related to the alternator than the ignition barrel.

Where should I turn now? I'm going nuts.

[the ferret]

Mate, you need to have a good chat with "Yendor"
He's the man.
Cheers, the ferret.

[Yendor]

The earth wire that connects to the alternator is not there to earth the alternator as such. The alternator's main earth is via the engine and then via the main negative battery cable.

The other end of the black wire connects to a couple of body earth locations. So I don't think this is your problem.

If you disconnect the two pin plug from the alternator does this turn off the battery gauge and red lights?

Is the original plug at the alternator still used or has this been replaced with single connectors?

[P4trol]

If you suspect something is draining the battery, disconnect both positive leads. One by one touch each individual wire on the positive terminal. (if yours is like mine and has 1000 add on wires to the terminals). With the ignition off of course. Watch for any sparks or small 'click' from the end of the wire.

The other way is use an ammeter.

Either trace the circuit or leave that wire(s) off and reconnect everything else. See what doesn't work.

On mine it was the radio/carpc.

[GQPorkroll]

Yendor, ill go and check that now. It's still the original Nissan plug on the regulator.

Patrol, tried that, no sparks when I connect either, but I can hear a click when I connect the main battery from the area the dual battery box thing is.

[GQPorkroll]

Yendor, yes, as soon as the reg wire is disconnected the dash lights/volt gauge goes off

[threedogs]

I trust we have avoided a Bonfire ????
Sounds like its one of 3 things
Bad earth, not charging or a short
Bummer no fire,

[Yendor]

Yendor, yes, as soon as the reg wire is disconnected the dash lights/volt gauge goes off

Your new alternator has issues.

You just need to make sure the White wire with a Red trace connects to the "L" terminal at the alternator and the White wire connects to the "S" and has 12 volts in it with ignition off.

I think this will be fine because you still have the original plug connected but it might pay to double check.

There is a good chance that your old alternator did have another problem that was causing the battery to go flat overnight.

[GQPorkroll]

Yeah I suspected the bloody new alternator the whole time as it was charging acceptably before, but I think the old alternator may have had the diode problem.

Ill double check the wires are going the right way but as it's the factory plug and it can only go on one way, I think the problem lies further inside. What a bastard, it was a prick of a job to fit it!

Cheers mate.

[GQPorkroll]

Wires checked, both going to the correct terminal, multimeter shows 11.9 V in white wire with key in the off position.

I suspected that bastard thing all along, it was too bloody hard to fit for it to work properly first time, FFS.

I think ill still look for a replacement dual battery setup to put my mind at rest. I think I should be able to source a good deal at work, got a trade show coming up soon. I'd prefer to have a bigger gauge wire and soldered terminals too.