Thanks for the responses.

I checked the fuse (and everything else) with a DVM.

The relay does click but stopped doing after my fooling with it for a bit. I assumed that there was some kind of protection built in so some idiot (me) would not be able to overheat the GPs by constantly turning the key on and off.

The fact that there are 4 used GPs in the drivers door is also a hint that there is something not quite right, but I don't know enough about these cars yet to take the hint. I suspect that the GPs in the engine are relatively new.

What gauge wire for the jumper? Battery cables

Dropout