Reversed Polarity

Where is the other end connected to?

mrcheerful

Not sure about the reversing charging, but could it be a red earth lead has been fitted? I had to buy a new earth strap for my new battery on one of my cars as I wanted a cheap battery and the original lead didn't fit, and the new one it red ratehr than black for some reason (even though it has the neg terminal on it).

You need to check what the other end is connected to. If it goes to earth, then no problem, you simply have a red earth lead. This is not a bad thing in itself, but you must be careful when changing batteries etc. An earth lead is quite likely to be brown nowadays anyway, are you sure this isn't the case?

It's possible someone in the past needed a new lead for the earth because the old one was knackered or too short to reach the 'new' battery, and happened to have a long red lead in the garage....

Either way, I would have a good look at what's connected where, and have the charging voltage checked. If your radio etc are working OK it's unlikely to be connected wrong way round.

Errr, it's not a moggy is it?

Steve

If you have been driving for 4 months and the car still starts ok and all the electrics are working then nothing is wrong and you've made a mistake. It would have died by now.

If the battery were reversed the starter motor would turn the wrong way and the radio would fail...at the very least.

Would it? Reversing the polarity on old +ve earth cars (like Minors) to make them

-ve earth involved little more than swapping over the battery leads and giving the dynamo a zap. The starter motor still worked correctly.

It would still turn the right way* , but the radio would go bang. Yes it is possible to reverse the polarity in a lead acid battery (once) but if everything works ok then its just a funny coloured lead .

Steve the grease

if it is the wrong way around, then the battery polarity can be reversed whilst it was charging (probably was charged off of the car) , ie,, the positive becomes the negative and the negative becomes the positive,

the problem with this is that the battery will not last as long. if this has happened i would serously get a battery of the correct type and polarity.

ITYM the battery won't last two seconds. If you connected a charged battery up th ewrong way round then I suspect so much current would flow that the loom would burn out.

What make car? Red is negative in some countries.

Ha. You have a look at what they've done with three phase wiring colour codes over the last few years.

At long last permanent wiring colours have been standardised in the EU - should have been done years ago at the same time as flex. Three phase is now brown black and grey with blue for neutral. It's not really a concern for the DIY electrician and a pro should soon learn them for his own safety. ;-)

Yes, but...

You're allowed to mix old and new codes on the same site, IIRC. And they are incompatible...

You're an idiot.

The colour doesn't matter a shit.

But the radio would go bang.

The message from "PC Paul" contains these words:

In what way are they incompatible?

So looking at the replies, the wires have been reversed too. I didn't think of that. Thank you for the re-assurance that I was missing the obvious. It looks like they've ended up swapping the wires around so the colour coding is wrong but they've attached them to the correct terminals for the electrics to work. I've rolled some red insulting tape onto the black wire and some black on the red one so I don't screw up if I ever need a jump start.

Thanks for the replies.

Warwick

well, what do YOU expect black to be? live or neutral? and what about blue? l or n ?

a wrong answer to either could kill you and either MIGHT be correct.

mrcheerful

However it's been permissible eto use black as live or neutral ever since flex went to brown blue. & if you're truly incapable of working it out from the other colours in the circuit then you're going to die from some other cause much sooner.

you must remember that he is a wise person coner, as he knows things in life that you do not, so by your own rule you also are a idiot.