Should the positive wire be hot?

Hi all

I have a TD5 90, from the battery positive to the main fusebox under the driver seat runs a positive cable. This is getting hot at the battery end, virtually too hot to touch. But only for a short amount of time when the ignition is turned, so guessing when the fuel pump is running, glow plugs ignited etc and there's a decent draw on that cable.
When the engine is running all seems ok.

There's a small amount of corrosion under the conduit battery end, guessing that's not helping.

Is this anything to worry about?

Thanks all

HR joint at the battery terminal connection?
Have it off.
Clean it up.
Put it back.

Do what @DanClarke says ... sex always helps in these situations

miktdish said:

Do what @DanClarke says ... sex always helps in these situations

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Especially if you put a lot of vaseline on your "bits"

Hahaha. Cheers chaps.

Should have made it more clear, it's not acrually the battery terminal connection. It's about an inch away from it. On this the actual battery clamp bolt is part of the cable. I spose I could cut back some of the conduit though, clean it up and heat shrink over it when clean.

ONE LIFE LIVE IT. D90 said:

Hahaha. Cheers chaos.

Should have made it more clear, it's not acrually the battery terminal connection. It's about an inch away from it. On this the actual battery clamp bolt is part of the cable. I spose I could cut back some of the conduit though, clean it up and heat shrink over it when clean.

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Sounds like it is "High Resistance" and maybe the conductors have cracked over time. There's lots of places will make up a new end to avoid any bad wire and splice it in. Specialist battery shops are a good bet.

ONE LIFE LIVE IT. D90 said:

Hahaha. Cheers chaps.

Should have made it more clear, it's not actually the battery terminal connection. It's about an inch away from it. On this the actual battery clamp bolt is part of the cable. I suppose I could cut back some of the conduit though, clean it up and heat shrink over it when clean.

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I would be putting a new cable on that asap.

lynall said:

I would be putting a new cable on that asap.

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I didn't think it was right either to be honest. But I'm not the greatest with electrics.

Wiring diagram states the original cable is 10mm². Anybody have an idea what amp cable is suitable?

That's a 70A cable ....
https://www.12voltplanet.co.uk/single-core-thin-wall-cable-10mm2-70a.html
Other vendors are available ...

ONE LIFE LIVE IT. D90 said:

I didn't think it was right either to be honest. But I'm not the greatest with electrics.

Wiring diagram states the original cable is 10mm². Anybody have an idea what amp cable is suitable?

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Same size, or bigger will do no harm.
Local garage will make it for you if you supply the bits, or they may even have the bits on the shelf.

As @lynall says, you should get it sorted asap, you will regret it if you let the smoke out ...

It's certainly possible for some cables to deteriorate whilst looking OK from the outside. Some copper alloys seem to go crisp and crumbly over time. The whole point of being careful about cable sizing is so they don't get hot! In the same way that you wouldn't want to wire your electric shower in with 15p per metre figure eight bell wire.