Bongo Fury

HI Peeps, is it a negative ground on a bongo or positive ?

Its a negative earth if that's what you mean? Didn't know there had been any +ve earthed cars around for years

mikeonb4c wrote:Its a negative earth if that's what you mean? Didn't know there had been any +ve earthed cars around for years

My old 1966 Mini van was positive earth. I remember I had fun fitting a stereo because the case was akways live!

Velocette wrote:

mikeonb4c wrote:Its a negative earth if that's what you mean? Didn't know there had been any +ve earthed cars around for years

My old 1966 Mini van was positive earth. I remember I had fun fitting a stereo because the case was akways live!

Ah Yes, happy days, I don't think I owned a -ve earth car until 1997 when I gave up driving firms cars.

Blew 2 radio cassette players in my mate's triumph herald before I discovered it was +ve earthed!

I destroyed a few sets myself, same way

Anything with an alternator will be neg earth.

Older dynamos can be either.

Hi
Come to think of it, when cars were positive earth...minis various, my old Standard, MG Maggot, Ford Consul convertible, amongst the many, I remember changing radios regularly...and that old +ve earth was normal...and the melting of the odd radio was, you say, a problem....rather causes me to remember...well................did I blow the odd radio......?????........NO....I always checked numerous cars had been fitted with alternate electrical systems, so it was a case of look carefully....and the coming of negative earth was always hailed as a ploy to arrest corrosion....did it make rusting less???????...did it 'ell.... ...damp + steel = RUST....ya can't change the laws of physics (or chemistry)...JIM
Cheers
Helen

helen&tony wrote:Hi
Come to think of it, when cars were positive earth...minis various, my old Standard, MG Maggot, Ford Consul convertible, amongst the many, I remember changing radios regularly...and that old +ve earth was normal...and the melting of the odd radio was, you say, a problem....rather causes me to remember...well................did I blow the odd radio......?????........NO....I always checked numerous cars had been fitted with alternate electrical systems, so it was a case of look carefully....and the coming of negative earth was always hailed as a ploy to arrest corrosion....did it make rusting less???????...did it 'ell.... ...damp + steel = RUST....ya can't change the laws of physics (or chemistry)...JIM
Cheers
Helen

I never blew the radio but as I had wedged it in with bits of wood, but I do remember the odd shower of sparks if something earthed accidentally contacted it!

military vehicles and most boats are + ground, helps to prevent corrosion apparently!

Julian

321Away wrote:military vehicles and most boats are + ground, helps to prevent corrosion apparently!

Julian

That's interesting because I'm sure people told me that the reason for the change to negative earth was to do with corrosion.

Velocette wrote:

321Away wrote:military vehicles and most boats are + ground, helps to prevent corrosion apparently!

Julian

That's interesting because I'm sure people told me that the reason for the change to negative earth was to do with corrosion.

Here's what t'internet says.

http://mechanics.stackexchange.com/ques ... ive-ground

and partly because positive earth encourages galvanic corrosion* of the surrounding bodywork - whearas with negative earth is is the much-easier-to-replace electrical contacts that corrode.

*Think back to school physics lessons with anodes and cathodes...

scanner wrote:

Velocette wrote:

321Away wrote:military vehicles and most boats are + ground, helps to prevent corrosion apparently!

Julian

That's interesting because I'm sure people told me that the reason for the change to negative earth was to do with corrosion.

Here's what t'internet says.

http://mechanics.stackexchange.com/ques ... ive-ground

and partly because positive earth encourages galvanic corrosion* of the surrounding bodywork - whearas with negative earth is is the much-easier-to-replace electrical contacts that corrode.

*Think back to school physics lessons with anodes and cathodes...

I liked the bit about thinking back to Physics lessons but all I can recall is jibber jabber annodes jibber jabber jibber jabber cathodes jibber jabber and sitting on the back row dicussing how my mate was going to fit 12" extended Triumph forks to his BSA!

Surprised nobody has yet mentioned changing the old cars from pos to neg earth. It was very easy.

I had a Morris Traveller (how I wish I hadn't let it go for £50 in 1972) and being a radio amateur I wanted to run neg earth equipment in it.

All we had to do was reverse the battery connections and If I remember correctly the generator field winding just needed a couple of blips of the new polarity to get rid of the old residual magnetism. None of the very few electrical items which a car needed in those days was fussy about the polarity including, as far as I remember, the starter motor. I may have had to reverse the power to that to stop it cranking the engine backwards but the only thing I can definitely remember was blipping the generator or dynamo, whichever we called it.


Frank

Diplomat wrote:Surprised nobody has yet mentioned changing the old cars from pos to neg earth. It was very easy.

I had a Morris Traveller (how I wish I hadn't let it go for £50 in 1972) and being a radio amateur I wanted to run neg earth equipment in it.

All we had to do was reverse the battery connections and If I remember correctly the generator field winding just needed a couple of blips of the new polarity to get rid of the old residual magnetism. None of the very few electrical items which a car needed in those days was fussy about the polarity including, as far as I remember, the starter motor. I may have had to reverse the power to that to stop it cranking the engine backwards but the only thing I can definitely remember was blipping the generator or dynamo, whichever we called it.


Frank

Exciting it I think they used to call it?, My Mum had a Renault 4 with a dynamo and 6V electrics, I later had a 12V one . Come to think of it you can make a 6V dynamo run at 12V too it is just the regulator you have to change. You could on Bikes anyway.