Help! No power XJR 2001 4.0 SC

[700SN]

Hi Paul,
With ignition off, I put the multimeter in Amp (mA) mode and red probe on red battery terminal and black probe on the negative earth strap hanging off the body.
No reading whatsoever!
That’s weird right?

[700SN]

And it’s still 12.83v...

[ptjs1]

Stu,

Not quite right. When measuring current flow, you measure between 2 points of a single line. So, the easiest way is:

- Connect the positive battery terminal cable to the positive battery terminal. You should still have the negative battery terminal disconnected.

- Set up your multimeter. This often requires you to change the red multimeter lead into the amps port of the meter.

- Set your multimeter to Amps. If there is more than one Amps setting, set it to the highest one. Also ensure it's on DC Amps, not AC Amps. DC Current is usually represented on a multimeter as a solid line with a dotted line underneath.

- Connect one of the multimeter leads to the hanging negative lead that has been removed from the battery.

- Connect the other multimeter lead to the bare battery negative terminal post.

The multimeter should now show the flow of current that is being drawn from the battery.

See the attached image which might clarify things.

Let us know how you get on!

Good luck

Paul

[700SN]

Cheers Paul, schoolboy error! Of course I did not do in series.. however I thought I’d leave the battery for another 3 days to see if it died - it didn’t! Shows still 12.7v
So then I did the Amps in series and nothing. Registers zero on mA and A.. using A terminal.

It’s weird, that it would appear it’s ok?

Cheers! Stu

[ptjs1]

Stu,

The battery voltage reading bodes well for the general state of the battery.

But, on a modern car like an x308, it doesn't feel right that you're getting absolute zero current draw? You had got the battery positive lead connected to the car? Also, you had changed over the red lead that plugs into the multimeter into the amps port?

Perhaps do that test again and get someone to turn the ignition on (NOT start the car!) and see the current draw on the ignition circuits.

Cheers

Paul

[700SN]

Thanks a lot Paul, I did as above and connected in series again with red cable in “A” port, in “A” setting while ignition in “on” position, neg clipped to neg strap and touching pos to the neg battery terminal but no current registered, which is quite strange!

[ptjs1]

Hmm, that's strange! And you've got the ignition in Position II and all the ignition lights are on?

That's got me confused! Let me think a bit...

Paul

[700SN]

Well, when fully connected for about 3 hrs I noted the voltage had dropped from 12.7 to 12.5..
Then I disconnected the neg battery terminal again and did the procedure as described, to check the Amps.
I had the ignition key in the on position, in order to connect the meter in series.
The pic shown is just that situation... cheers

[ptjs1]

Stu,

Just to be pedantic, when that current reading is zero, the ignition lights are all on?

Paul

[700SN]

Not at all Paul, you’ve been extremely helpful!
Indeed I even “extended” the negative terminal and the loose earth strap by way of jump leads, just so I could be about a yard from the dash.
I put the 2 together to make “normal” circuit...everything fine, internal lights, seats started to wake up, turned the key on ign , dash lights all on, all ok. Then broke the circuit, clipped the Multimeter cables to the respective ends to complete the circuit again.. complete ZERO reading, which is absolutely bizarre...

[ptjs1]

Stu,

Sorry, I wasn't quite clear in my question.

When you have the multimeter in series to check the current flow, are all the ignition lights on at the same time?

If they are correctly illuminated at that point, in theory you MUST have current flowing through the multimeter which is why I'm confused at that zero reading. If they are not illuminated, perhaps you are not making a sound contact with the multimeter leads either on the negative body lead or (more likely) on the battery negative post.

Hope that makes sense!

Paul

[700SN]

Hi Paul, no, when I break the circuit to put the meter in between, in amps mode, there’s no dash lights in and zero reading. I used 2 jump leads to extend to ensure I had a good connection on the terminals when I switched the ignition on, which was fine.
It’s only when I break the 2 leads apart and insert the multimeter clip on cables (neg to earth strap, pos to the one that is attached to the battery terminal) that there seems to be no reading and no current flowing through it that way...it’s as if the little cables on the multimeter just cannot take it or perhaps one is faulty.

[ptjs1]

OK, try the following:

1. Turn off ignition, remove key.
2. Take multimeter out of circuit.
3. Connect battery negative lead to battery
4. Check that interior light operates when opening drivers door.
5. Shut drivers door
6. Turn multimeter to Off
7. Disconnect battery negative lead
8. Connect multimeter in series again. Tray and find a way to connect the red lead on the negative battery post without you having to hold it. Maybe wrap a piece of wire around the post and connect the multimeter red lead crocodile clip to that wire
9. Turn multimeter to DC amps
10. Open drivers door, check interior light comes on
11. If light doesn't come on, shut door, go back and remake that connection again on the negative post
Repeat 10. & 11. as necessary

Cheers

Paul

[700SN]

Hi Paul, no luck I’m afraid, I’m sure it’s the multimeter at fault, because I tried the same process on my Sierra and exactly the same.

Noted also that there doesn’t seem to be any ohms reading either. Saying an open circuit sign on the display even if connected across battery?
I’m sending it back to Amazon. It was only 15 quid and it seems to have wasted yours & my time!

Guess I’ll have to get another better quality one and find out next week by using your procedure again ..

[ptjs1]

Stu,

No probs, always happy to tryb and help!

If you're making sound connections, it does sound as if there may be a fault with the multimeter. The only thing you might want to check is there is often a separate fuse on that 10Amp circuit onboard. You might want to check if that fuse is intact (perhaps its in the rear battery compartment?)

If you do end getting a new instrument, its always worth trying to get one that has that separate 10amp circuit for when working on vehicles.

Good luck

Paul