Thread: Question for those auto electrically minded

2.4A is a lot of current to just disappear. I'm surprised you can't track down the fault by following the smoke
It won't be an earth problem if you're still getting that amount of current draw. I assume you are measuring current draw in series with the +ve feed from the battery. If you've removed all the fuses and you're still getting current draw of 2.4A then you have to start blaming the Blue Seas fuse block for the problem - it really is the only thing that can be consuming, but I would expect the fuse block to get pretty hot. If it's not then I'd be checking the accuracy of the current meter.




Just as a mater of interest, how are you isolating the AUX battery from the cranking battery? Are you sure that these are disconnected.






Cheers
Pete

Originally Posted by captainslow

2.4A is a lot of current to just disappear. I'm surprised you can't track down the fault by following the smoke
It won't be an earth problem if you're still getting that amount of current draw. I assume you are measuring current draw in series with the +ve feed from the battery. If you've removed all the fuses and you're still getting current draw of 2.4A then you have to start blaming the Blue Seas fuse block for the problem - it really is the only thing that can be consuming, but I would expect the fuse block to get pretty hot. If it's not then I'd be checking the accuracy of the current meter.




Just as a mater of interest, how are you isolating the AUX battery from the cranking battery? Are you sure that these are disconnected.






Cheers
Pete

Thanks Pete,
I was using the negative cable as advised is much safer than using the positive and wont arc out if inadvertently earthed and will give the same result.
I found that there are several fuses drawing power, had to pull all out and insert one at a time.
I think I have found the issues as I will describe, but will go out and use the positive cable first. The current draw seemed a bit high to me, but this is basically a powered fuse block so certain things can run regardless of ignition on or off. Will be changing some back to ignition sources, but did not want items such as fridge HF radio to be on ignition. I assume what I am doing is right eg if negative cable used for amp check, main earth cable and earth pole for other earths on battery removed and joined together as would normally occur (optima battery with main +- poles and additional +- screw poles ). Would be the same with + end if I use this.
My set up and what I did find was the following:

1: HF Radio 30AMP Drawing Current constantly even though turned off.
2: GPO Rear Seat no current draw nothing plugged into GPO
3: Thermo fan no current draw
4: Thermo fan no current draw
5: Thermo fan no current draw
6: Amplifier Stereo Drawing Current even though turned off.
7: GPO Rear no current draw nothing plugged into GPO
8: GPO Rear no current draw nothing plugged into GPO
9: Elec brake power source Drawing 3 amps
10: GPO under centre console Drawing 3.6 amp with usb plug in but nothing plugged into usb. When USB plug removed no current draw.
11: Anderson Plug for Fridge. When fridge plugged in and turned off Drawing Current 3.6 amps. When cord unplugged from fridge no current draw.
12: Aux battery Voltmeter through switch Drawing current 3.4 amps with switch turned off (voltmeter not reading) I think this was a bit odd as a volt meter should only draw low current.

I know the easy answer is put everything through ignition and may be an option for a few of these items. But is certainly not for the fridge. I also dont want to put too much load through the existing ignition power eg the HF Radio needs 30amp heavy duty fuse.
Will check using positive cable and report back on here. Will also check using another meter. These are not cheap meters either one costing $140 and one well over $200.
Reading on 600a setting on clamp meter using leads.

Check.the battery on the meter, they read higher as the inter.al battery goes.flat.

You might also find that ~3A is the lowest step that the meter can display on that setting.

I'd start by using a normal meter on the ten amp scale.

Originally Posted by Blknight.aus

Check.the battery on the meter, they read higher as the inter.al battery goes.flat.

You might also find that ~3A is the lowest step that the meter can display on that setting.

I'd start by using a normal meter on the ten amp scale.

Dave,
You are probably right as I did not expect to see anywhere near that, maybe between 0.4 and 1 amp maybe. I will try using my SANWA meter, but that showed zero which cannot be right either, there would have to be some current draw.
Cheers
Craig

You might have a corrosion path to earth feoma positive somewhere

Craig, Are you using a clamp meter to measure d.c. current?
or has the meter got a d.c. Amps mode that uses plug in leads?
You mentioned using leads but I just wanted to check the obvious first.
IMO the clamp method can only indicate a.c. Amperes.
And on a 600A scale the measurement of low currents might be a little illusive - Is there a lower scale you could use?

You also may be seeing a current through the 2 batteries - the optima is just a path back to the main battery if they aren't isolated - I couldn't see where you mentioned an isolator and what type. Captainslow asked the pertinent question.

The circuit needs to be made clear/er before any stray currents can be "guessed". Cheers - Matti

Originally Posted by matti4556

Craig, Are you using a clamp meter to measure d.c. current?
or has the meter got a d.c. Amps mode that uses plug in leads?
You mentioned using leads but I just wanted to check the obvious first.
IMO the clamp method can only indicate a.c. Amperes.
And on a 600A scale the measurement of low currents might be a little illusive - Is there a lower scale you could use?

You also may be seeing a current through the 2 batteries - the optima is just a path back to the main battery if they aren't isolated - I couldn't see where you mentioned an isolator and what type. Captainslow asked the pertinent question.

The circuit needs to be made clear/er before any stray currents can be "guessed". Cheers - Matti

Matti,
I have 2 meters 1 x Digitech clamp meter that also has leads and a SANWA multi meter.
The digitech is a high voltage unit and 600a is probably giving an incorrect reading however indicates something. The SANWA must be having some issues as it is showing zero and that cannot be correct either. Will replace the inbuilt fuse in it and check again, wrapped fuse so cannot tell if it has blown.
While the digitech may be over reading it would still be where there is a drain from some areas. With the reading when pulling fuses it did drop to zero when certain fuses were removed. May be acceptable limits though.
The issue I have is there must be some sort of drain as it is flattening a fully charged battery in less than a day with an engel running that I used to get 4 - 5 days out of. The battery does appear to be ok.
Dual battery system with a TJM system solenoid and control box. May be possible the solenoid is cactus.

Originally Posted by matti4556

Craig, Are you using a clamp meter to measure d.c. current?
or has the meter got a d.c. Amps mode that uses plug in leads?
You mentioned using leads but I just wanted to check the obvious first.
IMO the clamp method can only indicate a.c. Amperes.

There are clamp meters available for DC, I use mine quite regularly on low current draw applications, it has shown to be quite accurate at low current draw