IOD Fuse - Help Needed
 

Got in my GV yesterday morning to run an errand and surprise surprise, my new battery didn't even have enough charge to light the instruments.
So today, with the ignition off, I checked the current draw of every fuse under the bonnet but only the IOD fuse was drawing any power. With interior lights switched off, radio switched off and doors closed, the IOD fuse was still drawing
between 0.87 and 0.88 amps.
So with the engine running I checked the voltage at the battery terminals, expecting to see 14 plus volts. I was only seeing 12 plus. Now suspecting the alternator is not charging, I disconnected the neg terminal on the battery but the engine kept on running. So I've removed the IOD fuse and I'll leave it unplugged for a few days to see what happens.

The low-amper-age IOD should not exceed twenty-five milliamperes (0.025 ampere) Al, yours is pulling up to three times the expected.

7 live items
Remote key fob
Radio
Heater blower
Folding mirrors
Central locks
Interior lights when the key is in the ignition

Most brand new batteries are less than 25% charged at delivery

Can I assume you did not switch off, lock doors and alarm on ?

Can I assume you did the metering with the bonnet open and the post not taped down ?

Can I assume you tested that before the 20 minutes 'sleep' function kicked in ?

Can I assume you did not do the buttonMOD ?

I charged the battery with mains charger.

Tests were done with ignition off, doors unlocked and alarm off.

Correct.

Tested after 15 minutes.

I haven't done the MOD yet. Still waiting for somebody to explain where the resistor goes. ;)

So today I will be taping down the under bonnet alarm switch, doors locked and wait 20 minutes for it to go to sleep. I'll report back later.

I think you're on the right lines with the alternator charging voltage.

(BTW Don't run the car with the battery disconnected, spikes and surges esp if the Alternator and diode pack are dodgy could fry the ECU)

Even before doing buttonmod (Which btw the resistor goes on the connector. As you face the back of the car, under the battery housing, feel under with your hand and to the left nearest you corner you'll feel a connector. Wiggle it and drop it out, that's the connector that goes into the 'button'.
Even when the temperature sensor is at it's worst it should still give more than 12v at charge,

From my testing years ago, if you disconnect the battery temperature sensor, the system will default to full charge and give you around 14v, so maybe do that and see what you get, that will confirm if it's the temperature sensor (buttonmod) causing low charge, or if your alternator/diode pack is shot and need replacing.

PS, I finally found the previous conversation QinteQ and I had about voltages, IOD draw, etc. and to confirm what I found:
So it sounds like yours is never entering sleep mode.

So after waiting and testing you should see the IOD draw drop right down, it sounds like yours isn't so onto testing the list that QinteQ said. My first port of call would be the radio, seeing if it switches off, do your electric windows still work after power off, key out?
Also maybe pull the auto shutdown relay to see what current that drops you to (nearest to front bumper, left of IPM box).

It's a game of elimination, but we're getting closer!

Thanks Andy, I'll be going through QinteQ's suggestions this afternoon then work from there.

There's a buttonMOD walkthrough with pics on Andy's blog somewhere. Perhaps Andy can point you to where Al.

Thanks QinteQ,I'll have a look for it once I solve the current draw problem.

I have just looked for it for you but couldn't find it on either blog or tube M8. You might have to wait till he tells you where.

The story so far:
Tied down the underbonnet alarm switch with a cable tie.
Locked the car and waited 20 minutes. Current draw remained at 0.87.
Disconnected the radio-SatNav and current draw immediately dropped to 0.05 amps.
Disconnected the (faulty) DVD player and re-connected the radio. Current draw went back to 0.87.
So I've disconnected the radio again and I'll leave it unplugged for a few days to monitor the results.
I've also put a volt meter on the battery terminals, started the engine and revved it to 3000 rpm expecting to see the voltage rise to at least 13.5 volts but it remained at 12.5.
I'm wondering if my radio-SatNav draws more ignition off current than the standard radio's.

One+

Explains lots Al, and yes anecdotal evidence on the GV almost always points to the Radio as the first culprit for parasympathetic 'off draw'.

Hi folks,

I thought I'd written a blog entry about it, but maybe not as I can't find it either! Will have to do that!

Yes radio is a common one, remember there are two components with the radio, the head unit itself and the rear amplifier (hidden behind the rear right hand side speaker).

How did you disconnect the radio, fuse/relay in the IPM or by unplugging the head unit? My recent playing around with the head unit and amp has discovered the amp in mine has constant 12v feed to it regardless of ignition/radio state and it seems to power on and off based on a signal over the CANBUS, so depending on what way you've disabled your radio will help pinpoint the head unit itself or the rear amp.

Quick one, when keys are off/removed from ignition, wait 5 mins, then try turning radio on, will it turn on? Does it constantly show the clock?
That's one that's cropped up before due to a dodgy wiring change that forced the ignition sense to have constant 12v and so it never enters sleep.

Also, that alternator charge voltage of 12.5v to me sounds like it's not working at all! So engine off and voltage is 12.5v and with engine on/alternator running it's 12.5v too? Again I'd say disconnect the battery button sensor and try that again see if any difference. If not then I think you've got two issues, one being the alternator is shot.

Well I heard this morning that KwikFit are doing a free battery and alternator check. So I drove round to my local KwikFit for the test. They reported that the alternator was good but that the battery needed a good charge.
However, on the way there I noticed that the speedo isn't working and the alarm isn't working. I reconnected the radio in case the 12 volt loop through was affecting the speedo but that made no difference.
I previously disconnected the radio by unplugging both plugs at the rear of the head unit.

Ah ok, so charging circuit sounds like it's just low, fair enough.

Hmm, no the connectors at the back of the radio will just stop it sending the 'on' via canbus to the amp in the rear, the amp will still have it's feed to it (but in theory be in sleep) so looks like it might be the head unit itself.
There isn't anything I'm aware of that would stop speedo and alarm working when radio unplugged, I've done that a few times recently whilst working on it, driving with radio completely disconnected with no adverse effect, which leads me to believe there may be something else going on here too.
Was it just speedo non-operative or other gauges too? Did it do a dash sweep before start and if so, all gauges do it inc speedo?
Sorry for more questions and little answers, just quite a few things to narrow down, but I've got to admit this is sounding more fishy.

All other gauges, including rev counter and even the milometer and trip mileage are working fine. No dash sweep at all. The alarm system isn't working but the LED alarm indicator is on permanently while the ignition is on.
Edit: And I'm pretty sure my head unit doesn't have an amplifier in the rear. I checked for that a couple of months back.

The alarm is working again. I plugged that little ammeter into the IOD fuse holder and the alarm beeped. So I unplugged it, put the fuse back in, closed the bonnet and locked the car. The alarm LED started flashing rapidly for 16 seconds as it's supposed to. But the speedo still isn't working. I've noticed that one of the relay's is marked as 30A - Central AMP but even with this unplugged and the radio disconnected, the IOD current draw is till 0.87 amps.

Is the speedo needle on top or below the pin ? Reset procedure Al.

If you have used jump cables or had an alternator spike,reset anyway

That's brilliant QinteQ. I had to use a slightly different procedure but it did the trick and now my speedo is working again. Until you asked the question I hadn't even noticed that the needle was below the pin. I'll try to post a video on the procedure I used to do the reset.

My video on how to do the speedo reset.

Edit: After posting my video I found a few other videos on the same subject.

Just a quick update:
Opened the drivers door yesterday morning and the alarm activated. Checked the battery voltage which was 11 volts (radio is still unplugged). Tried to start the car and the engine sprung into life almost immediately?
I removed the battery from the vehicle and connected it to a mains charger in my garage. At 16:00 yesterday the charger was indicating the battery was fully charged so I disconnected the charging leads and left the battery off the car overnight. This morning it was reading 11 volts again, even though there was no load on it. I'll monitor it off the car for another couple of days but I suspect that my new battery is US.
One other point, while I've been having these power problems, when the alarm activates, usually caused by opening a door when the battery voltage is less than 11 volts, the alarm continues for a minute or so before it silences itself. Then it activates again for a minute then silence. This goes on for several minutes until presumable, the battery in the alarm runs down.

Aha, good work AlanC, yes I'd agree sounds like battery failure if it's not retaining charge at all.
The alarm is because of the drop in battery voltage, but sounds like it then drops too low and the alarm cuts out due to battery failure/too low voltage to power the electronics.

Glad you've got further on it, back to the shop with that battery!

I think I've finally solved my battery drain problem. I was previously measuring the Ignition Off Draw via the IOD fuse. With the radio connected it was drawing 0.87 amps reducing to 0.05 with the radio unplugged. I left the radio unplugged for over a week but the new battery was still going flat within 2 or 3 days. Today I decided to measure the current draw using a multi-meter connected between the battery + post and the battery + cable. With the ignition off and the car locked I was seeing a draw of 1.4 amps!
So with the multi-meter still connected I started removing each fuse in turn until I pulled the fuse for the Amp. The current draw dropped to 0.03 amp.
I don't understand why the amp is drawing current with the ignition off or why the power to the amp doesn't got through the IOD fuse.
So I'm thinking of treating myself to a new head unit for Christmas but I realise I'll have to figure out how to wire the speakers back to the new unit.