radiator fan electrical problem

[erotomania]

I've narrowed it down I think to a bad wire

The ignition switch works fine
The cooling fan relay is good
The fuses are not blown
The thermosensor is good
The fans work

I checked the four terminals where the cooling fan relay plugs in

with ignition ON:
I get 12V on one terminal
continuity to ground on another
continuity to the fan on another
and nothing on the last one

I am supposed to be getting 12V on the last one with the ignition on II.

Who knows which color wire this is?

The shop manual says there should be a Bl/Y wire running to the relay in the fuse box but there is no Bl/Y wire going in there.

[erotomania]

I am referring to the diagram on page 10-9 on Paul's shop manual.

[joebeets]

Looking at 88 efi fan relay: blu/blk goes to fan; blu goes to fan temp switch, closed above 90 C; yel/wht comes from timer; final connector is hot at all times from fuse 9.