No, I'm not that old!. But I well remember trolleybusses in Bradford and trams in Huddersfield. I was a little kid when trams were in Hudds. and they used to frighten me, with their blunt shape. The trollies were very deceptive. Over the double back wheels the seats were sideways, and the set-off acceleration was so high you could end up lying down on the seat. This in complete silence except for the odd conversation. I got to look in a rectifier house one time in Bradford, and it was eerie. Two monstrous 3-phase mercury arc rectifiers were sitting there in the darkness with the plasma arcs playing around on the mercury bath in the pool at the bottom, making the mercury sparkle as the arcs played. There was a gentle buzzing all the time, changing slightly as the arcs moved. It was like a scene out of a pre-war science-fiction film.
Sad to say, the Bradford trollies were finished in 1974. I witnessed the final ceremonies in Leeds Rd. tramsheds as I lived ony 5mins. away then.

Back to business -- the IOD fuse mod. is having a definite effect. There is obviously far less drain on the batteries at rest and parked after a few days now. Curiously, the original IOD fuse fitted in my GV. was 20A., my 20mm fuse is 5A quick-blo, and it's not blown. If this circuit is a draw of 100mA or so, why a 20A fuse? Someone must have replaced it with a wrong fuse before I got the vehicle maybe.

Leedsman.

 

I expected about a 30% reduction in draw after 20 minutes at rest with the IOD out. Are you saying you pull 100mA after 20 minutes of resting with the IOD in ? BTW the IOD fuseholder unlike all the others in the IPM has a ledge built in to it that allows a the fuse to securely sit on the side waiting to be re-inserted. Best of luck my friend.
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IGNITION-OFF DRAW TEST - reproduced from the workshop manual - NOTE - My Bold.

The term Ignition-Off Draw (IOD) identifies a normal condition where power is being drained from the battery with the ignition switch in the Off position. A normal vehicle electrical system will draw from fifteen to twenty five milliamperes (0.015 to 0.025 ampere) with the ignition switch in the Off position, and all non-ignition controlled circuits in proper working order. Up to twenty-five milliamperes are needed to enable the memory functions for the Powertrain Control Module (PCM), digital clock, electronically tuned radio, and other modules which may vary with the vehicle equipment. A vehicle that has not been operated for approximately twenty one days, may discharge the battery to an inadequate level. When a vehicle will not be used for twenty one days or more (stored), remove the IOD fuse from the Integrated Power Module (IPM). This will reduce battery discharging. Excessive IOD can be caused by:

• Electrical items left on.
• Faulty or improperly adjusted switches.
• Faulty or shorted electronic modules and components.
• An internally shorted generator.
• Intermittent shorts in the wiring

If the IOD is over twenty five milliamperes, the problem must be found and corrected before replacing a battery. In most cases, the battery can be charged and returned to service after the excessive IOD condition has been corrected. (1) Verify that all electrical accessories are off. Turn off all lamps, remove the ignition key, and close all doors. If the vehicle is equipped with an illumi-nated entry system or an electronically tuned radio, allow the electronic timer function of these systems to automatically shut off (time out). This may take up to twenty minutes. (2) Disconnect the battery negative cable. (3) Set an electronic digital multi-meter to its highest amperage scale. Connect the multi-meter between the disconnected battery negative cable terminal clamp and the battery negative terminal post. Make sure that the doors remain closed so that the illuminated entry system is not activated. The multi-meter amperage reading may remain high for up to three minutes, or may not give any reading at all while set in the highest amperage scale, depending upon the electrical equipment in the vehicle.

The multi-meter leads must be securely clamped to the battery negative cable terminal clamp and the battery negative terminal post. If continuity between the battery negative terminal post and the negative cable terminal clamp is lost during any part of the IOD test, the electronic timer function will be activated and all of the tests will have to be repeated. (4) After about three minutes, the high-amperage IOD reading on the multi-meter should become very low or nonexistent, depending upon the electrical equipment in the vehicle. If the amperage reading remains high, remove and replace each fuse or circuit breaker in the Integrated Power Module (IPM), one at a time until the amperage reading becomes very low, or nonexistent. Refer to the appropriate wiring information for complete Integrated Power Module fuse, circuit breaker, and circuit identification. This will isolate each circuit and identify the circuit that is the source of the high-amperage IOD.

If the amperage reading remains high after removing and replacing each fuse and circuit breaker, disconnect the wire harness from the generator. If the amperage reading now becomes very low or nonexistent, ELECTRICAL/CHARGING - DIAGNOSIS AND TESTING) for the proper charging system diagnosis and testing procedures. After the high-amperage IOD has been corrected, switch the multimeter to progressively lower amperage scales and, if necessary, repeat the fuse and circuit breaker remove and re-place process to identify and correct all sources of excessive IOD. It is now safe to select the lowest milliampere scale of the multi-meter to check the low- amperage IOD. CAUTION: Do not open any doors, or turn on any electrical accessories with the lowest milliampere scale selected, or the multi-meter may be damaged. (5) Allow twenty minutes for the IOD to stabilize and observe the multi-meter reading. The low-amperage IOD should not exceed twenty-five milliamperes (0.025 ampere). If the current draw exceeds twenty- five milliamperes, isolate each circuit using the fuse and circuit breaker remove-and-replace process in Step 4. The multi-meter reading will drop to within the acceptable limit when the source of the excessive current draw is disconnected. Repair this circuit as required; whether a wiring short, incorrect switch adjustment, or a component failure is at fault.

 

The 20A fuse is correct, this is from the manual:
George

 

100mA [1/10 of one ampere] is quadruple [ish] what the IOD should be drawing at sleep mode, that's close to a 30 day month to discharge to completely empty a biggish battery. I looked at this issue a couple of years ago [post on this forum] and decided in my case, given my lifestyle [once a week only use] I only needed to replace any loss over 0.025 ampere which I managed to do with a cheepo maplins solar charger to avoid (1) a flat battery or (2) needing to pull the IOD to survive a week or so. That solar managed to keep the I/O benefit neutral, because I had no winter problems at all from the day I plugged it in. This of course only apples to a given normal 0.025 ampere draw at sleep, and not something more excessive such as 100mA at sleep.

 

I'm just wondering if Leedsman has an issue of moisture in a plug or socket causing this parasitic draw of power. I suppose every plug you pull should be sprayed with moisture dispersant as well as checking for corrosion and cleaning. A chaffed/cut/split underbody wire or plug holding moisture would be same I suppose. Nice one to get answer too...Lets open a bottle of Sparkly if you do...

 

I'm astonished how much writing this posting of mine has generated so far, and I've not even finished testing!

Leedsman.

 

REPORT SO FAR ON IOD. SWITCHING:--

1) IOD. current after stabilization -- falls to 32mA plus odd pulses to 40mA every 20secs. or so. This is the current flowing thru' the IOD fuse. This current never is much bigger.

2) Battery all-off current (except IOD current): Starts at 800mA for a couple of minutes or so, then falls to 35mA, then falls to 32mA plus odd pulses, obviously the IOD current. All doors shut etc.This was an easy measurement for me as my #2 battery has a terminal switch on the +ve pole-post. All I had to do was connect the ammeter across this switch while "on", disconnect the #1 main battery -ve pole, and switch off the terminal switch of battery #2, thusly indicating the current flowing. No fiddling about here. No loss of power and losing the radio-code.
3) I tested my two 2.4watt. solar panels as to charge current while I had all the test equipment out, it was 28mA, overcast sky (3:30 pm.) and the panels mounted on the parcel shelf bottom of windscreen. The batteries were fully charged. I'm going to assume this very low charge current will balance out the natural self-discharge of the two batteries, one of which, the #2 battery, has only 5mA known self discharge.

Conclusions so far? Switching-off the IOD circuit obviously reduces the battery drain to nil, but doesn't cater for the natural self-discharge of the lead-acid batteries. The solar panels should do this near enough, with occasional driving doing the rest.

BUT, there is an unanswered question here; why would the voltage reading over a period previously show sharper falls? After a few days the battery voltage could be down as low as 12.4volt. Whereas now it's just under 13volt after the IOD switching mod.
Curious: I read on another website re. GV's battery problems, that one man had discovered his GV's micros were switching things on in the middle of the night while he was tucked up in bed. Can't remember his rationale, but his wife had something to do with discovering it.
Anyhoo, ready for winter now, I'll see how starting the engine goes with no help from the electricity grid, just a stand alone vehicle. I'll shoot and publish the picures shortly as to how to do the mod. It needs some fine soldering skills, but maybe there is another way of connecting to the blade-fuseholder in the fuse panel not needing such skills. Perhaps fabricating some blades like a fuse and putting a right-angle bend in those blades to go in a minature terminal-strip connector.

Leedsman.