Tip for the day - Check the ground beneath the computer connector.

[Manolito]

I got out the voltmeter to find the common wire from the secondary air pump to the relay plugs so I could figure out which relay controls the air pump.

I quickly realized that the problem with the air pump was not the hot wire, it was a poor ground connection. Traced the ground wire down to.... "Holy Cow! Look at all that corrosion!" There is a 10 mm bolt welded to the inner fender directly below the computer connection where you plug in your code scanner (exhaust side of engine). It has two big ground wires connected to it. Mine was terribly corroded. Crudded up like an old battery terminal bolt. Shocking since everything else under my hood looks like new.

Took off nut and cleaned everything with steel wool. Reassembled and sealed with NoCo spray. Secondary air fan works fine now. I suspect that other things that depend on that ground will work better as well.