Help - my car won't start either!

pitkin2020

jamesb1239 wrote: »

I was always told that it was positive to positive, negative to chassis. Something to do with surges etc

you are correct, negative from the running car to a good metal contact on the dead car

Wig

jamesb1239 wrote: »

I was always told that it was positive to positive, negative to chassis. Something to do with surges etc

Negative to any "clippable" non moving part of the engine is what you can do, yes even chassis if you have a bit where there's no paint. But it's not really necessary and easier to instruct a beginner to do it battery terminal to battery terminal.

roger196

Wig wrote: »

Negative to any "clippable" non moving part of the engine is what you can do, yes even chassis if you have a bit where there's no paint. But it's not really necessary and easier to instruct a beginner to do it battery terminal to battery terminal.

Rather dangerous for positive earth cars, produces a rather exciting fire. First check which terminal goes to earth.

Zanzibar

"Rather dangerous for positive earth cars"

Don't think any modern car is - think you probably have to go back 30 years (poster said their car was 5 years old). Maybe there are some - do you know of any out of interest?

Wig

roger196 wrote: »

Rather dangerous for positive earth cars, produces a rather exciting fire. First check which terminal goes to earth.

What cars have +ve earth? I'm not doubting you, but all cars I've seen inside the engine bay, have had -ve earth. If they are plentiful and not as rare as hens teeth then it would be a good idea to check that.

goldspanners

jamesb1239 wrote: »

I was always told that it was positive to positive, negative to chassis. Something to do with surges etc

red to red black to back and blew to f**k! well it would be in the case below

roger196 wrote: »

Rather dangerous for positive earth cars, produces a rather exciting fire. First check which terminal goes to earth.

i honestly have never seen an positive earth vehicle in my life, apparently they do exist,the only reason i think they exist is due to the fact older cars did have a warning that this vehicle was negative earth.

DaveMacD

goldspanners wrote: »

red to red black to back.

Not always.... Vauxhall Combo van has a Red cable at the Negative terminal..... Check the symbols on the battery. + to +, - to -.

roger196

Zanzibar wrote: »

"Rather dangerous for positive earth cars"

Don't think any modern car is - think you probably have to go back 30 years (poster said their car was 5 years old). Maybe there are some - do you know of any out of interest?

Sorry to take so long to reply but I had hoped to find my book on classic cars. From memory many cars built in the 50's and 60's were positive earth eg MGB, Bentley etc. Production was changed back to negative earth on the alleged grounds it improved corrosion resistance.
I can remember radios had a switch for which type of earth you had. Also people changing their cars to negative earth from positive. The cables/ connector markings were not always changed, so you had to be careful. Another thing to watch out for was those cars which ran on 6 volt ( eg Ford Popular which also had windscreen wipers driven off the inlet manifold...as you went uphill and the engine slowed, so did the wipers...great in heavy rain)

Wig

So what you're saying Roger, is that it's pointless checking for +ve earth before jumpstarting unless you have a really old classic car, and if that was the case any keeper of such a car would already know all of its idiosyncracies?

goldspanners

DaveMacD wrote: »

Not always.... Vauxhall Combo van has a Red cable at the Negative terminal..... Check the symbols on the battery. + to +, - to -.

in this case you would be blew to f**k then.