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[JamesV6CDX]

Driving home with project Elite, I stopped in the services, checked under the bonnet. Noticed that the neg terminal was too hot to touch, scalding hot.

Later on, noticed that the positive one was red hot, but negative one was cold.

Obviously an electrical fault.

The smaller engine management wires do not get hot, it's just the thick ones going from battery to starter via alternator. And I guess I'm right in thinking, that this is the only circuit in the car not fused?

With the ignition on, but no engine running, the lead doesn't even get warm.

But as soon as the engine's run for a couple of mins, it gets red hot, at the terminal end.

Ideas? I was thinking Alternator, based on the above......

[Kevin Wood]

Try measuring the voltage across the battery when it's running. Could be regulator failure in the alternator overcharging the battery.

Also, make sure the connections at the battery are in good condition, especially where the charging lead from the alternator meets the battery clamp.

Kevin

[JamesV6CDX]

Try measuring the voltage across the battery when it's running. Could be regulator failure in the alternator overcharging the battery.

Also, make sure the connections at the battery are in good condition, especially where the charging lead from the alternator meets the battery clamp.

Kevin

I was just thinking of putting my known good alternator on there, during the rebuild

Could there be anything else causing it, but alternator?

[Marks DTM Calib]

Or the starter is not disengaging.....is the starter feed from the ignition switch turning off....

[Kevin Wood]

If it only happens when it's running I'd say it's either the alternator or the quality of the wire / connections at the battery terminals. If there is a little resistance here it will get hot when it's passing the output of the alternator. Probably more likely to be the latter TBH but I guess if you've got a known good alternator it's going to be much easier to change it with the heads off.

Kevin

[TheBoy]

Could feasibly be a fault with the battery...

[JamesV6CDX]

Ok, so far, replace battery (got known good one) and replace alternator!

[spiridusul_rau]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

[TheBoy]

Ok, so far, replace battery (got known good one) and replace alternator!

If Alternator shot, I would expect batter voltage to be above 15v at 3000 rpm...

[JamesV6CDX]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

That will be a bit tricky with the cylinder heads off it

I will replace all the likely culprits whilst apart, and take it from there.....

[TheBoy]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

That will be a bit tricky with the cylinder heads off it

I will replace all the likely culprits whilst apart, and take it from there.....

Errr, do it before taking heads off!

[JamesV6CDX]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

That will be a bit tricky with the cylinder heads off it

I will replace all the likely culprits whilst apart, and take it from there.....

Errr, do it before taking heads off!

That would mean fitting inlet manifold, inlet bridge, coolant bridge, plenum, bagpipes.... remember I've already started stripping the other day

[TheBoy]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

That will be a bit tricky with the cylinder heads off it

I will replace all the likely culprits whilst apart, and take it from there.....

Errr, do it before taking heads off!

That would mean fitting inlet manifold, inlet bridge, coolant bridge, plenum, bagpipes.... remember I've already started stripping the other day

I would have checked before I started stripping....

[spiridusul_rau]

 

[JamesV6CDX]

Hi,
first you must measure the voltage of the battery with engine off. Then start the engine and measure again the voltage.

That will be a bit tricky with the cylinder heads off it

I will replace all the likely culprits whilst apart, and take it from there.....

Errr, do it before taking heads off!

That would mean fitting inlet manifold, inlet bridge, coolant bridge, plenum, bagpipes.... remember I've already started stripping the other day

I would have checked before I started stripping....

I'll renew the alternator, starter, battery anyway with bits off the other car, and cabling.. there is not much else it can be.....