Turns out after all the messing that it was the battery, but to be fair it was acting strange, showing strong voltage on the multimeter but as soon as the key was turned, the amp-age dropped like a stone.

Swapped it out with a new one and it's all good - Valdas also spotted the thermostat was on the way out - Aux fan never kicked in and Engine temp was a solid 108' on the OBC - Now at a lovely 90-95'

Also changed out the oil and filter as it was probably a little burnt so it's ready for the winter ahead.

Next time I'll listen to the 10 people in a row telling me it's the battery! :-)