3 yellow are generator - that much should be obvious :)

the others are +ve and -ve

You have 2 chances to fit them correctly - wrong, and the main fuse will blow (so get a spare) and right..then you're sorted.

Magg is right though - you may be masking other issues with the reg rec unless the current one has melted already...

Of all the long time posters on the site - Magg would be the one I would be asking for electrical guidance - so heed the words!