• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

battery cables

Share this page

S

sabot

Jedi Trainee
Offline
ok, stupid question time,
on the 67 spitfire i just picked up,

the negative cable is going to the starter relay and the positive cable is going to the frame.

Is that correct? or how can i tell for sure thanks tom
 
I concur with Don. Positive ground (earth) is typical of British cars of that vintage.
 
It almost doesn't matter unless originality is a concern, or someone has fitted some electronic components to the car. The ignition coil is the only original component that is polarity-sensitive; and it's easy enough to swap the wires at the coil. (Also won't hurt anything if it's wrong, just might not run quite as well.) Personally, I'd probably convert anyway, just so I didn't have to worry about it being different, could fit an alternator or stereo if I wanted, etc.

But I agree with the others, Spits stayed positive ground (positive cable to the frame) until the Mk IV (1970) even though TRs went negative ground in 65.
 
thanks for the info guys,

one more stupid question, if i leave it positive ground, will that be a problem if i ever have to jump start it?

brain dead after all these years, tom
 
I (reluctantly, since I don't have my manuals in front of me!) beg to differ. I'm pretty sure that most, if not ALL, Mk3 Spitfires, were negative ground. I believe the change occurred in 1967, possibly coincident with the introduction of the Mk3.

I'll try to double-check this tonight at home. Meanwhile, if anyone has a later edition of the factory workshop manual for the Herald/Vitesse/Spitfire, it does tell there.

Meanwhile, jump starting is not a problem regardless, so long as you make sure + goes to + and - goes to -.
 
You would get a better response if you start another posting so the title reflects your issue.
 
Andrew Mace said:
Meanwhile, if anyone has a later edition of the factory workshop manual for the Herald/Vitesse/Spitfire, it does tell there.
Click to expand...
I do (although it's the Brooklands reprint, magnifying glass not included) and in fact was looking at it (with magnifying glasses
grin.gif
) when I wrote the above post.
 
sabot said:
if i leave it positive ground, will that be a problem if i ever have to jump start it?
Click to expand...
Just be certain there is no other conduction path between the two vehicles (like the bumpers touching) and it will be fine.
 
TR3driver said:
Andrew Mace said:
Meanwhile, if anyone has a later edition of the factory workshop manual for the Herald/Vitesse/Spitfire, it does tell there.
Click to expand...
I do (although it's the Brooklands reprint, magnifying glass not included) and in fact was looking at it (with magnifying glasses
grin.gif
) when I wrote the above post.
Click to expand...
Interesting, since my original (black vinyl binder) Workshop Manual has a specific "Section 3" in "Group 6 (electrical...)" stating: "Information contained in this section deatils electrical equipment specific to the following vehicles that are all fitted with a negative earth electrical system.

Herald 1200 from approximately March 1968
Herald 13/60 introduced in October 1967
Spitfire Mark 3 introduced in March 1967."

Is there something different in your Brooklands reprint, or did I miss something in a smiley? :confuse:
 
I'll have to check it when I get home tonight. I was looking at a wiring diagram labelled "Spitfire Mk III" that showed the battery positive connected to ground.

Dunno what happened to the black one, must've let it go with the Sports 6.
 
Not to belabor the point, but the Spitfire Mk3 Spare Parts Catalogue, Second Edition, lists part number 515997 -- Lead, battery negative to body to engine earth lead, and part number 516873 -- Lead, battery positive to solenoid. Puzzling, meanwhile, about that wiring diagram; does it have a page number?
 
Boy, do I feel stupid !

You're absolutely right, Andy ... checked the diagram again and it does show negative ground.

Oops!
 
TR3driver said:
Oops!
Click to expand...
Not to worry; we're all allowed the occasional gaffe! Maybe you do need a bigger magnifying glass, though. For the life of me, I don't know why those reprints are done half-size. Yeah, I understand saving money, but we older folk still working on these older cars need bigger print. :crazyeyes:
 
hi guys,

positive to ground, negative to solinoid is the way it is set up.

but the book says it might not be that way?
did they do it as positive ground up to March 67, then change to negative ground?
sorry, i'm not sure how you guys include statemants from previous posts.
cut and paste?
tom
 
Tom , Just go to the post you want to quote and hit the Quote or Quick Quote button.
 
Would steer ya wrong.

Lots easier now than it use to be.
 
sabot said:
positive to ground, negative to solinoid is the way it is set up.

but the book says it might not be that way?
did they do it as positive ground up to March 67, then change to negative ground?
Click to expand...
Well, Andy's quote would make it appear that all Mk 3 Spits were negative ground. That doesn't mean there weren't some positive ground Mk 2s titled after March 67, though; or possibly even a "personal export" Mk 3 that got titled before then.

So the question becomes whether your car is a Mk 3. What's your commission number (VIN) ?
 
Back
Top