Battery drain - cause?

[HotWheelsBurban]

I guessed (but didn't want to believe) that PCM could be the Power Control Module. Was clueless re the VCM.
There's nothing aftermarket apart from the LPG (which I'm confident isn't the problem) and a weird set-up for the gauge backlighting. There is an additional switch (which changes the colour of the lighting) and a pot - so two methods of dimming. I had a good look at all that and couldn't find anything amiss.
What's making things more difficult is that on the 10A range the MM isn't sensitive enough to pick up small changes and when set to 200mA range that current spike blows its fuse.
Your description re capacitor sounds (very) plausible.
The other non-standard set-up - but not aftermarket as such is the external lighting system. It doesn't (just dawned on me - I haven't actually checked this) have DLR (which I had assumed were in the lower lamps but are a dimmed headlamp). In my lower lamps I have parking lights and another light with orange bulbs as indicators (turn signal). At the rear, the reversing lights have been converted the same way and an external reverse light mounted below the bumper (visible in avatar pic). Maybe something in all that lot.

Not sure how much I did before is valid as multi meter had blown fuses so think I'm starting from scratch again. PITA!

Seems like the export type lights might be the place to start looking once you get your meter sorted out. There's a member on here called Jermu97 in Finland, who has a 97 pickup. His truck had some different lights on it because of their regulations, and he had to sort out and replace some of them. I think the build thread is called "Pancake " because that's the truck's name. Very interesting story behind that, which I'm sure he'll tell you. He might have some hints for you too, since y'all have been having similar problems. There's some Aussie and New Zealanders on here too. Good luck!

 

[HotWheelsBurban]

There's a green indicator light on the dash that is for the DRLs. It's always on until the headlights are turned on. The high beams indicator is similar looking but it's blue, and it's only on when the high beams are used. The dimmer switch is the turn signal/cruise control/ windshield wipers switch (GM calls this the multi function switch). For high beams, pull this toward the steering wheel; you may hear or feel a click. To return to the low beams, pull the switch toward the wheel again. To flash the headlights, do this twice quickly. Bear in mind, my trucks were built in Mexico, but for the US market, so yours being a European export model may be different. Did you get the owner's manual with it?

 

[Pinger]

There's a green indicator light on the dash that is for the DRLs. It's always on until the headlights are turned on. The high beams indicator is similar looking but it's blue, and it's only on when the high beams are used. The dimmer switch is the turn signal/cruise control/ windshield wipers switch (GM calls this the multi function switch). For high beams, pull this toward the steering wheel; you may hear or feel a click. To return to the low beams, pull the switch toward the wheel again. To flash the headlights, do this twice quickly. Bear in mind, my trucks were built in Mexico, but for the US market, so yours being a European export model may be different. Did you get the owner's manual with it?

Going to have a look at/for that today. Double pull for flash then? Maybe I do have flash after all. I could use it. Are the brake lights live without ignition? If so, another thing to check.

I got quite a lot of reading with the truck. Handbook/owners manual, Haynes manual, build sheet, a bunch of receipts for recent work/parts - it all helps (especially the handbook/owners manual).

 

[HotWheelsBurban]

That's good that you got that much paperwork with your truck. We got the owner's manual and the options list in the glove box on the first truck, kept the manual from it for the second one. So often when buying second hand you don't get much. I also have the first 3 volumes of the fact Chevy shop/ service manuals. Lost the 4th volume, it's the one that has all the body stuff in it. I remember when GM had a service manual that had most basic tasks, and an overhaul manual which had the rebuilding procedures. My Dad's 2006 GMC Yukon XL Denali has 6 books in the shop manuals set, for around $400-$500. We just got the Haynes for it, and went to the local library for their database for what it didn't cover. I have a Haynes book for the 99 Burb too.

 

[Pinger]

Haynes manual for me is a translation guide (UK English to USA English)!

 

[Pinger]

I did say on another thread confessing to a 'doh' moment that there may well be more. Fill yer boots, here it comes.
Nothing wrong with my battery. Nothing draining it either. The first time it flattened was due to multiple starts with the alternator disconnected. The second time I must have left something switched on.
The confusion was down to using a multimeter as ammeter with blown fuses. The readings were wrong and the initial current seen on connecting to the battery is nothing more than circuits in the truck being energised and will fall to a lower current as soon as that is achieved. It will also blow fuses in a MM.

So, for anyone ever tracing a battery drain using an ammeter.
There is a procedure to connect the ammeter without blowing fuses. It is awkward to do but basically, with the battery still connected to the truck, connect the MM in parallel then remove the battery connection to the truck. The MM will now be in series and will have been saved the current spike.

Where I messed up was relying on figures on an MM which had blown fuses and continued to display but wrongly. A cheap ($8) MM also blew a fuse on the 200mA scale. But it then showed no readings. Fitting the test lead to its unfused 10A scale gave correct readings.

Anyway, the upshot of this is that the truck fired up this morning after having been sat since Saturday with the battery connected - a reasonable test. That, and the (correct) current readings on the MM showed a drain of 10-20 mA - well below the accepted limit of 60mA.

So a problem solved that was never a problem. I should be happy about this - when the feeling of 'doh' stupid wears off - maybe I will be!

Thanks everyone for the help - and apologies for the runaround.

 

[RawbDidIt]

I did say on another thread confessing to a 'doh' moment that there may well be more. Fill yer boots, here it comes.
Nothing wrong with my battery. Nothing draining it either. The first time it flattened was due to multiple starts with the alternator disconnected. The second time I must have left something switched on.
The confusion was down to using a multimeter as ammeter with blown fuses. The readings were wrong and the initial current seen on connecting to the battery is nothing more than circuits in the truck being energised and will fall to a lower current as soon as that is achieved. It will also blow fuses in a MM.

So, for anyone ever tracing a battery drain using an ammeter.
There is a procedure to connect the ammeter without blowing fuses. It is awkward to do but basically, with the battery still connected to the truck, connect the MM in parallel then remove the battery connection to the truck. The MM will now be in series and will have been saved the current spike.

Where I messed up was relying on figures on an MM which had blown fuses and continued to display but wrongly. A cheap ($8) MM also blew a fuse on the 200mA scale. But it then showed no readings. Fitting the test lead to its unfused 10A scale gave correct readings.

Anyway, the upshot of this is that the truck fired up this morning after having been sat since Saturday with the battery connected - a reasonable test. That, and the (correct) current readings on the MM showed a drain of 10-20 mA - well below the accepted limit of 60mA.

So a problem solved that was never a problem. I should be happy about this - when the feeling of 'doh' stupid wears off - maybe I will be!

Thanks everyone for the help - and apologies for the runaround.

You live and you learn, thanks for the update.

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[Pinger]

You live and you learn, thanks for the update.

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If you call this living.....

 

[RawbDidIt]

If you call this living.....

Sometimes surviving qualifies lol.

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[HotWheelsBurban]

You just do what you have to do, one day at a time. I'm lucky that I have a job, but my employer has several people who are out(some sick, some maybe just lazy)so my boss is giving me extra work. I didn't want to be working on my truck on mother's day, but looks like I probably will be. First world problems, I know. It's just frustrating.....
On the good side, I got to take my mom for mother's day lunch yesterday, and we got to dine in for the first time in 2 months. I almost forgot what it was like to do that.
Pinger, glad you finally figured out what the deal was with your truck. One of the things I learned from dad was that sometimes you have to do something what turns out to be the wrong way, to figure out how to do it the right way. Thanks again for your kind words and assistance. I may just have to tackle the manifold gaskets myself, later on this year. First I need to do the oil change and front pads, didn't get to them last week because of work. I want to see what's still making noise in the front end after I paid for that to go away....It usually happens when going over speed bumps, so it's straight up and down movements. I'll do the check with the long board and see what it does. Then I have an idea what to fix next....