Can't start, won't start

[Robotsan]

I bought these for my rally car , work very well ( clamp very tight) and have the points for extra cables

Nice one, I was looking at these exact ones, thanks!

 

[yellowz]

Not sure what cable size it equates to but both pos and neg cables are 11mm external diameter

 

[Robotsan]

Not sure what cable size it equates to but both pos and neg cables are 11mm external diameter

Cheers Jim! And do you have all those additional wires too? The thin red one off the positive lead and the 2 black ones off the negative?

 

[yellowz]

No
One big black wire (think it should be red) going down to the starter with two small white leads going into the loom coming off the +
One big black wire going to an isolator switch in the glove box and back out to earth coming off the -

Your battery is the other way round to mine

 

[toopy]

What gauge should the black lead be? And should they both be the same?

Re: the other wires - are you sure it's not just because it's a 280z? I've found pics of other 280z batteries online and they seem to have the same wiring. For example:

I’ll be back – [Battery] Terminator

Every now and again, i jump in the car to fire it up only to find it won’t start. No ‘click’, no turn over. Baaaahhhh now what is it?! After a few times of this happening over the…

dailydatsun.wordpress.com

That sort of wiring shenanigans is definitely not OEM. People add 'accessories' over time which can end up a mess as in the image in that link. Adding one is acceptable and can still be neat, but really there should be an additional small fuse box/holder for anything more.

 

[Robotsan]

No
One big black wire (think it should be red) going down to the starter with two small white leads going into the loom coming off the +
One big black wire going to an isolator switch in the glove box and back out to earth coming off the -

Your battery is the other way round to mine

OK, interesting. Well I can see the 2 white leads coming off your positive is exactly the same as mine (except my pos cable is red!), so that's the same on both cars, and the same as the photos of other 280s I've seen.

And sounds like yours has an aftermarket isolator then which is why that's different to mine.

If yours is the other way round I guess someone has altered it so that you can use normal UK batteries.

 

[toopy]

Some people buy batteries that have terminals the opposite way round (if your original cables will accommodate the swap), mainly i believe because the positive can be dangerously close to the bodywork, obviously for the earth this then doesn't matter.

 

[Robotsan]

That sort of wiring shenanigans is definitely not OEM. People add 'accessories' over time which can end up a mess as in the image in that link. Adding one is acceptable and can still be neat, but really there should be an additional small fuse box/holder for anything more.

Fair enough, I'll get it looked at. I've been told there's an old boy in the area who's an auto electrician so planning to find him and get a few things sorted!

But it is weird that its the same on Jim's car and the other photos of 280s online... those same white plugs coming off the positive lead seem to be on all of them:

 

[yellowz]

Could not swear to it but this looks stock as goes into the original loom. Top end of the two wires is in with the positive lead to the starter.

 

[candy red]

Earth to starter motor connections need to be really crlesn as this can be a massive drain on cranking amps common problem on even modern cars

 

[Robotsan]

Could not swear to it but this looks stock as goes into the original loom. Top end of the two wires is in with the positive lead to the starter.

View attachment 56185

Yeah same on mine. Could be a major coincidence, but evidence suggests that particular wire is original.

 

[Robotsan]

Some people buy batteries that have terminals the opposite way round (if your original cables will accommodate the swap), mainly i believe because the positive can be dangerously close to the bodywork, obviously for the earth this then doesn't matter.

I like the sound of this, might make that change as it does look risky having it right under the wing.

 

[yellowz]

I like the sound of this, might make that change as it does look risky having it right under the wing.

I would. On the first Z I had I seem to remember seeing a really bright light and holding the warmest spanner in the world.

 

[Robotsan]

Decided to paint and lacquer (heavily!) the old battery hold down clamp thing so that should be a bit safer now! But I will also try and insulate the positive cable a bit more in the short term and then get the new clamps and cables on soonish.