Positive earth

[New Bloke]

I bought the car from an enthusiast who popped a battery into it to get me going. The fact that the fuel pump didn't work due to wrong polarity and now the engine runs, the red light stays on, leads me to wonder if it has been converted to negative earth at some stage????

I'm thinking of reversing the pump back to how it was and swapping the battery around. There are no peripherals like radios fitted so I'm wondering what harm could it do to check. Planning on trying today after work.

Thoughts anyone?

[ManyMinors]

It shouldn't be THAT easy to fit a battery the wrong way around because the positive and negative terminals are different sizes - the negative being smaller. They should also be marked so it should be fairly easy to work out how the car was wired.

The standard fuel pump is not polarity sensitive so should work either way.

[New Bloke]

I don't think it is a standard fuel pump, it only works one way 'round, on another threasd someone suggested it was an aftermarket addition and an electronic pump.

I'm fairly sure it's not going to do any harm and if the dynamo has been flashed to work the wrong way then that would explain why the red light stays on.
I think the battery clamps seem to have been not fitted full on anyway.

[bmcecosse]

If the pump works as it was - then yes the battery must now be wrong way round, which explains the red light. Either swap it (and the pump) back - or repolarise the dynamo and swap the coil terminals over -and clean the dizzy points. If an early gold fuel gauge it will also need the connections reversed.

[New Bloke]

Cheers everyone, I swapped it over but still got the ignition light on, some kind of troubleshooting now required I fear.

[oliver90owner]

Extremely unlikely, because beam me up hasn't thought about it, but the charge control box may need swapping round. Most certainly did on early 1960s Fords, when changing polarity.

[bmcecosse]

There may be a problem with the dynamo of course - but to repolarise it all you need is a lead from the NON earth terminal of the battery and 'flash' it against the smaller terminal on the dynamo a couple of times.

[New Bloke]

Brilliant, thanks for the advice chaps, getting to work on that over the weekend.

Cheers