Boot light keeps blowing fuse

[Chris Hogg]

Yep, I had one of those. Don't remember how I plugged it in though.

[Brian Reay]

There is a formula to calculate it. If my memory serves it is called Peukert?s Formula but I don?t remember the actual formula beyond it isn?t linear.

Like you, while I agree the low discharge rate will help improve the available capacity, it won?t be that dramatic. Plus, you should work on only have the marked capacity actually being available, unless you want to risk damaging the battery ( at least if you discharge beyond this point regularly). Car batteries are not designed to be deep discharged- leisure batteries are a different matter but can be limited when it comes to peak currents.

Modern cars are often fitted with remarkably small (in Ahr terms) batteries. 35-45Ahr isn?t uncommon. I?m pretty sure my CRV was 45Ahr, my MX5 35, and my wife?s Picanto also 35Ahr. Our daughters often left the interior light on in the Picanto and my wife found the battery was dead the next morning.

[Steve Walker]

Yes, we had one. One (5W?) bulb instead of four left on. Ours didn't have the rubber arm it was a flat sided, isosceles triangle shape, with the narrow point flattened off and a springy metal clip attached there to hook over the window.

SteveW

[Steve Walker]

On the other hand, I once had my car doors frozen shut and borrowed my mother's Fiesta 1.6 diesel to get to work on time (this would have been in 1990, so a basic, non-turbo diesel).

The battery was not good and when I came to go home, the interior light had drained it enough to stop it from starting. Trying to start took the rest out out of the battery and trying to tow start it (bump starting it was not an option due to the compression ratio) wouldn't work, because the battery no longer had even enough power to open the fuel cut-off valve!

SteveW

[T i m]

<snip>

I wonder how many people know ... and how many cars do it that if you leave the indicator indicating right (or left etc) with the ignition off and lights on side, you just get the single light front and rear on the right? So two 5W lamps (plus side repeaters) instead of 4 (traditionally).

Cheers, T i m

[charles]

my father's light was magnetic. When plugged into the retro-fitted 2 pin socket it would stick to the bodywork. (Magnalite?)

[charles]

5 - you forgot the numberplate light

[charles]

My 1971 Cortina III did that.

[Chris J Dixon]

As I said last time you mentioned this, this is a DIY group, so in addition to the Woolworth's socket, you shouldn't leave out the mention of making your own parking light from a bit of bent tin can, a fish paste jar, a bulb holder and a red sweet wrapper.

Chris

[tabbypurr]

A red pie tray works pretty well too. DAMHIKT.

NT

[Tim+]

One of these?

Tim

[Bob Eager]

Was common on Fords for decades. I know it stopped for a bit (not sure why). No idea if they do it now (and I have a Ford!)

[Tim+]

Common in VAG cars. Don?t think you have to leave side lights on, you just need to leave the indicator switch in the appropriate position.

Tim

[The Natural Philosopher]

Ah the old 1.5V polarised battery connectors. Also used as AM radio aerial socket I think.

[NY]

I never knew about it, and I had two VW Golfs (1988 and 1993 vintage). I only learned about it much later. I suppose if someone hadn't already told you about it, you'd only discover it if

- you happened to leave the indicator switch in one of the two "on" positions when you parked at night

- you *didn't* leave the side lights switch on which would override the one-sidedness

I always cancel my indicators manually when I've finished turning: I got into that habit after driving my dad's Citroens which didn't have self-cancelling indicators. I actually prefer non-self-cancelling indicators - I find I have to hold the switch on when indicating right on a roundabout because the initial left turn to join the roundabout cancels the signal.

I presume with the advent of LED lights, fewer cars nowadays need one-sided lights for parking, because the current drain from 4 lights will not be noticeably more than from 2.

I think I first learned about one-sided parking lights when I asked in a newsgroup about the wiring in towing hitches - why they "wasted" a pin by having separate pins for left and right tail lights when they could have used it for something useful like fog or reversing lights, which the older

7-pin connectors don't have. When we had a caravan, my dad ran a separate wire for reversing lights with an inline fuse connector which had one part on the car and the other on the caravan; part of the hitching-up-and-testing-lights was to make sure that wire was connected and that the reversing lights on the caravan came on.

After asking about this, people said "oh, it's so you can leave just one rear light illuminated when parking at night" which made me realise that this was evidently possible in some cars.

I remember my friend's dad had one of those little red-and-white lights that you clipped onto the window when you were parking at night, so your car showed a white light forwards and a red light backwards without you needing to leave the side/tail lights on. That used even less power - a single 5 W bulb with white and red "glass" on the front and back respectively.

[charles]

Not the one on my father's car that had a circular plug.

[T i m]

<snip>

Check.

When I turn off the ignition with an indicator left on, the lights off and then open the door I get an audible warning (which is different to the one if I just leave the lights on) and *generally* I just (subconsciously) cancel whatever it is that I've left on to silence the warning before leaving the vehicle (which is why I thought you had to leave the lights on but you don't on this Meriva A).

I wonder if it was the same on my Mk5 Cortina or Mk1 Sierra (I don't think I ever tried to use it on the Rover 218SD and as that was possessed [1], it would probably take over and change things in any case). ;-)

Cheers, T i m

[1] It would seemingly randomly (centrally) lock and / or unlock itself, even if you were in it.

I once just stopped at the side of the road outside a shop and because I was only putting something though the letter box, just closed the car door. A couple seconds later I heard it central lock itself (with all the keys now locked inside). Whilst I had a spare set at home, I couldn't get in till the Mrs was available but considering it was a Honda under the Rover badges, went into my local motorcycle shop and borrowed (with permission) a Honda key from a 125 Honda motorbike. It opened the car straight away. ;-)

More 'public' was when it immobilised itself (I didn't have an immobiliser fob etc) just as we were supposed to be driving off the I.O.W ferry. ;-(

[NY]

Embarrassing. I bet you held up the whole queue in the IOW ferry :-( The nearest I've done to causing a major hold-up was when my clutch cable snapped as I was setting off when I was the lead car at traffic lights. Because this made the car stall in-gear, there was no way to get the car into neutral so it was jammed solid. And because the car was on a slight slope, it was difficult to rock the car uphill to relieve the pressure on the transmission that was jamming the gear lever. Eventually two burly guys came to help and were able to move the car uphill to let me put it in neutral, so I could roll backwards out of the way.

I was once behind a car that wouldn't start as it was about to drive off the Lymington/Yarmouth IOW ferry and I was impressed with how quickly the port staff arranged a vehicle to tow it clear so everyone else could get off. It must be a common occurrence for them to have a towing vehicle readily available.

When I got a house and a car of my own, I very quickly learned the habit of always keeping the keys in my pocket apart from when they were in the front door lock or the car's ignition - and always removing the car keys (and, nowadays, locking the car) whenever I got out, even for a brief instant. I used to leave my car unlocked (though not with the keys in) while I went into the kiosk to pay for fuel; not any more!

So far I've not managed to lock myself out of my house/car, and I very rarely lose my keys because *by definition* they are in my pocket if they are not in the lock that they operate.

It means that if I ever have to leave the house in a hurry (eg fire, flood etc) then I will always have my keys - as long as I have time to get dressed ;-) And even if I didn't, I'd know where to grab my trousers on the way out so I had my keys.

I'm probably unusual: a lot of people empty their keys out of their pockets at night and hang them on a rack (implicitly 'labelled' "car thieves, here are the keys"), and also put their keys down somewhere while they are doing something else. I wish I had a tenner for every time we've been about to go out and SWMBO says "where are my keys" and we have to go on a hunt for them. OK, I'm as bad with my reading glasses - now I need them even for using the computer and cutting up veg for dinner, as well as for reading, I really ought to put them on a cord round my neck, except that looks naff and like something my grandpa used to do ;-)

[dennis]

No but the battery or charger were broken and needed fixing. I haven't said that it wouldn't drain a faulty battery.

[invalid]

8<

Its not just the alarm system, the computers are still powered up. You can get a clamp on meter and measure the drain and it can be several watts without lights or alarm.