Is there an auto-electrician in the house?

[ClichéGuevara]

Well, prompted by this thread, I thought I'd get down to investigating an electrical problem the car's had for many months. I have no idea what actually happened, but the battery went flat due to being stood too long, and there was a prolonged, torrential downpour. A replacement battery left some of the dash lights not working, and the lights coming on when they felt like it when I was driving, and were then independent of the control switch.

On seeing this, I searched the net for a wiring diagram, and found a choice of loads, each with different functions for the fuses, so I bought a multi-pack box with every rating of fuse, which arrived today.

When I finally found the fuse box, it was obvious that I may have had every conceivable rating, none were the right physical size, and there was a whole choice of dimensions fitted to the car.

As I'd already got of my backside, I thought I'd pull each fuse in turn to see if I could find the used one, and make sure I got the correct replacement.

Each one was fine, so I stuck it all back together, and gave the car a quick spin to check I hadn't cocked something else up, and it seems I've resolved the original problem, and everything now works fine.

I have no idea what I've done, beyond effectively turning it on and off, but I think I'm now a level one auto electrician, having passed my own test.

 

[fossyant]

Get yourself a solar trickle charger if the car is so little used.

 

[13 rider]

Has the manufacturer done any software update to the Engine management unit . I had a new car and used it just for weekly food shop once a week during lockdown and had battery drain issues . Manufacturer recall for update and cars now fine with similar usage

 

[presta]

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.

70mA for one week is 12AH.
If you have a ~40A alternator, it's going to take 15-20mins to replace just that, and then in addition it has to replace the charge used by the starter motor and everything else in use whilst you're driving. How long does it take you to drive 5 miles?

 

[raleighnut]

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....



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 .

Which are those?

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

View attachment 606782

and

View attachment 606783
View attachment 606784

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

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

you can get stickers

 

[swee'pea99]

You have answered your own question
I think you need one of these get the 10 watt one
https://www.ebay.co.uk/itm/324250988123?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908105057&meid=6fb3880be5c64a9cae1177342da1924e&pid=100675&rk=1&rkt=15&sd=324250988123&itm=324250988123&pmt=1&noa=1&pg=2380057&brand=Eco-worthy&_trksid=p2380057.c100675.m4236&_trkparms=pageci:28298b3a-098e-11ec-a1a7-96fa9191fbd3|parentrq:970ac4a517b0ab8e9a8fbca4ffedc25e|iid:1

Get yourself a solar trickle charger if the car is so little used.

Thanks. Ooh, that looks promising! Green too - the girls will approve!

Has the manufacturer done any software update to the Engine management unit . I had a new car and used it just for weekly food shop once a week during lockdown and had battery drain issues . Manufacturer recall for update and cars now fine with similar usage

I don't think so. Long story short, it's 13 years old, and was previously owned by someone who worked at a main dealer, so I'm guessing if there were any such, it would've got 'em.

70mA for one week is 12AH.
If you have a ~40A alternator, it's going to take 15-20mins to replace just that, and then in addition it has to replace the charge used by the starter motor and everything else in use whilst you're driving. How long does it take you to drive 5 miles?

The reading I'm getting is millivolts rather than amps. Don't ask me why Scotty reckons that's the way to go about it - I just do what I'm told.

The solar thingy looks like it could be just the job. Does anyone know if it would actually work via the cigarette lighter socket? It would certainly be a boon, compared to having to connect to the battery. Not that it's necesarily a deal-breaker - I have no great objection to drilling holes through the back of the glove compartment if it's necessary. Perfectionist, that's me.

Again, many thanks to all for ideas/suggestions. I really do appreciate it. And if I can work out the technicalities, the trickle charger does look like it might be exactly what I need.

 

[ClichéGuevara]

Does anyone know if it would actually work via the cigarette lighter socket? It would certainly be a boon, compared to having to connect to the battery. Not that it's necesarily a deal-breaker - I have no great objection to drilling holes through the back of the glove compartment if it's necessary. Perfectionist, that's me.

Again, many thanks to all for ideas/suggestions. I really do appreciate it. And if I can work out the technicalities, the trickle charger does look like it might be exactly what I need.

I'm far from an expert, but my thoughts are that it would depend if your cigarette socket is live when the ignition is off. If it isn't, I don't think it will work, and you'll need to wire back to the battery terminals, or other point before the ignition.

 

[numbnuts]

Thanks. Ooh, that looks promising! Green too - the girls will approve!

I don't think so. Long story short, it's 13 years old, and was previously owned by someone who worked at a main dealer, so I'm guessing if there were any such, it would've got 'em.

The reading I'm getting is millivolts rather than amps. Don't ask me why Scotty reckons that's the way to go about it - I just do what I'm told.

The solar thingy looks like it could be just the job. Does anyone know if it would actually work via th? It would certainly be a boon, compared to having to connect to the battery. Not that it's necesarily a deal-breaker - I have no great objection to drilling holes through the back of the glove compartment if it's necessary. Perfectionist, that's me.

Again, many thanks to all for ideas/suggestions. I really do appreciate it. And if I can work out the technicalities, the trickle charger does look like it might be exactly what I need.

I had one on my car during lockdown and work very well, most cigarette lighter socket are live just plug in and leave it on the dash

 

[figbat]

If you are looking to check all the fuses, I would start with the circuits that are permanently live rather than ignition-controlled ones.

 

[neil_merseyside]

Don't try and cherry pick which fuses as you'll obviously miss the iffy one.

 

[Drago]

you can get stickers

Snickers melt if you leave them in the glovebox.

 

[Milkfloat]

I had one on my car during lockdown and work very well, most cigarette lighter socket are live just plug in and leave it on the dash

To add to the confusion, some will stay live for about 30 minutes only after the ignition is turned off / car locked.

 

[numbnuts]

To add to the confusion, some will stay live for about 30 minutes only after the ignition is turned off / car locked.

Alway with the "Negative Waves" ..........it comes with alligator battery clamps in that case

 

[gbb]

Given the car doesnt get used much, that's a possible major factor as PaleRider states. Trickle charge once a week would do it the world of good if you cant get to use the car much...or take it for a 20 mile drive once in a while.
Starting a car uses a lot of power, add background use while the car is sitting there, a 5 to 10 mile trip just isnt going to replenish whats being used.

 

[Milkfloat]

Alway with the "Negative Waves" ..........it comes with alligator battery clamps in that case

I think you need positive waves as well to keep the battery topped up.

When I had a ‘garage queen‘ I kept the battery in tip top condition with one of these.

View: https://www.amazon.co.uk/gp/product/B00FC42HAA/