Is there an auto-electrician in the house?

[swee'pea99]

Ok, so my battery keeps going dead. Got a new battery, had the alternator checked out, everything's a-ok, but the new battery's gone dead, after a couple of months. So, googling brought me to a gentleman called Scotty who is American and rather loud, but does seem to know his stuff. Anyway, I followed his instructions, involving a setup like this:

...connecting the negative lead and the negative terminal, and where Scotty says I shouldn't have to worry about a reading of anything up to about 35 millivolts - because modern cars use at least some electricity just sitting there - it turns out my reading is around 70, which means something is indeed causing a drain.

According to Scotty, I now need to remove fuses one by one till I find the one whose removal drops that number to whatever it should be, and bingo - my problem's somewhere in the circuit connected to that fuse. Ok, makes sense.

Then I look in the manual and find there's not one fuse box but two, and each has something like 20 fuses in. So I was just wondering, does anyone out there have any handy household hints & tips about how to narrow this down a bit. Or is it unavoidably a case of just working through the fuses one by one.

Hope this makes sense and that someone can help. As is I'm sure very apparent, I'm out of my depth here, but I like to try. Thanks for any advice/hot tips.

 

[fossyant]

Stuck on boot light or glove box light ?

 

[Cycleops]

At least you found Scotty Kilmer.
I should check the bigger value fuses first, the most likely offenders.

 

[Drago]

How quickly is the battery going flat? If its quick, itll be something big like current draining to ground through a faulty starter motor or alternator. If it takes days then itll be something less thirsty. Thatll at least give youmsome ide which circuits to check first.

Oh, and check the boot light goes off when the boot is closed. Thats the common one.

 

[numbnuts]

Faulty alarm, I had this, no sound, but the indicators use to flash for a few minutes and then go off again

 

[Bonefish Blues]

How quickly is the battery going flat? If its quick, itll be something big like current draining to ground through a faulty starter motor or alternator. If it takes days then itll be something less thirsty. Thatll at least give youmsome ide which circuits to check first.

Oh, and check the boot light goes off when the boot is closed. Thats the common one.

And don't forget to let her out afterwards.

 

[raleighnut]

fit one of these

Battery Isolator switch

If you cut a hole in the wing to fit in you can con on that you compete in some form of motorsport

 

[bikingdad90]

I would check the obvious locations first such as the door openings to see if there is a split in the wiring under the rubber sheathes allowing water ingress? I would then check the radio amp and radio system followed by the alarm/deadlock system and then interior lights. After that I would revert to the removal of fuse one by one as I wouldn’t know where to go next.

 

[Smokin Joe]

Put your phone on video and shut it in the boot then the glovebox. That will tell you if one of those lights is staying on.

 

[swee'pea99]

Thanks very much everyone. I know it's not the boot light, because when John checked the alternator and installed the new battery he said he'd also taken the liberty of removing the boot bulb just to rule that one out because 'no-one ever needs it and that's often the problem'. I'll check the glovebox using the Smokin Joe video tip - nice one!

Other than that....

How quickly is the battery going flat?

Not massively quickly. Had the new battery installed in mid June, so it's taken two months and change to get to dead. It's not the alternator or starter motor, because those were checked out back in June, and got the .

I should check the bigger value fuses first

Which are those?

In case it helps, the diagrams in the manual look like this:

and

Faulty alarm, I had this, no sound, but the indicators use to flash for a few minutes and then go off again

Thanks, but (after two & a half months) I'm pretty sure we would have noticed if it was this.

As a final thought, does the fact of it being about 70 millivolts actually point to any particular likely candidate(s)? Ie, 'it can't be the door lock, because that wouldn't cause such a drain, or the ignition coil, because if it was that the figure would be much higher'? As I say, I'm pretty clueless, but I like to learn, and it's a 12 step programme, right?

Thanks again - really appreciate it.

PS

fit one of these

View attachment 606678

Battery Isolator switch

If you cut a hole in the wing to fit in you can con on that you compete in some form of motorsport

Wouldn't that mean I'd have to paint a number on the door? I'm not sure 'er indores would approve...

 

[fossyant]

How long is the car standing before the battery goes flat, or is it going flat when car in use ?

 

[swee'pea99]

How long is the car standing before the battery goes flat, or is it going flat when car in use ?

Good question! These days the car sits outside for days on end doing nothing. (Used to go for a daily spin till Cassie died. *sniff*) Probably doesn't do much more than a five or ten mile trip a week, plus maybe three or four multi-hundred mile trips a year. So, with that kind of usage it took as I say maybe a couple of months to go completely flat.

 

[numbnuts]

Good question! These days the car sits outside for days on end doing nothing. (Used to go for a daily spin till Cassie died. *sniff*) Probably doesn't do much more than a five or ten mile trip a week, plus maybe three or four multi-hundred mile trips a year. So, with that kind of usage it took as I say maybe a couple of months to go completely flat.

You have answered your own question
I think you need one of these get the 10 watt one
https://www.ebay.co.uk/itm/32425098...rentrq:970ac4a517b0ab8e9a8fbca4ffedc25e|iid:1

 

[Cycleops]

I should check the bigger value fuses first, the most likely offenders.

Ones with 15, 30, 25 printed on top.

As above the fact you let it stand for days on end might be the answer. This knackers the battery very quickly. But if its a new battery.

 

[Pale Rider]

Good question! These days the car sits outside for days on end doing nothing. (Used to go for a daily spin till Cassie died. *sniff*) Probably doesn't do much more than a five or ten mile trip a week, plus maybe three or four multi-hundred mile trips a year. So, with that kind of usage it took as I say maybe a couple of months to go completely flat.

Given that all modern cars drain the battery slowly while standing idle, I also suspect your use of the vehicle is the problem.

In other words, battery use of designed in drain and one start per week is slightly greater than the amount of charge generated by the short journey.