Do the L test.
Gerard, you are mixing us up as far as the "Sequence of Events". Please explain the sequence of events. You say fuse blows, tried the test wire, fuse does not blow, took off linkage fuse blows................we don't know when test wire was used during these events. Please advise when old hot wire was used and when new hot wire was used.
We want you to use ONLY the test wire and a inline fuse on B. Confirm you have a wire directly from the battery to an inline fuse holder, out the holder to B.
Do the L test