Thanks Mark, I just learned about test pins that are available that do just that and I have a set coming. Hopefully I won't need them for the fan issue as I think the R5 relay replacement has cured the problem. They may be helpful in solving the alternator light especially if I can find a way to get a hand in behind the alternator to use them.

 

Don't want to sound like a broken record but you want to make sure you have eliminated the possibility of bad battery cables.
They can often deteriorate beneath the insulation where you can't see the problems.

Also bad earthing points are an issue that also keeps popping up for may reasons and faults.
The oddity is that where you have an earthing stud and multiple lugs going onto a stud, the order they are stacked on the stud seems to matter to the factory engineers.

 

in post #21I said R5 but ment R7 I may have done that in other places so watch out. I don't see how to edit a post.