Sorry, I did miss that you had a bad module. I opened mine up and examined it thoroughly and found nothing visually. Everything in there looked like new. It's a pretty complicated module with what looks like a micro-controller (Toshiba chip), supporting logic and a relay for the pump. I was able to trace the relay contacts to the pump under the hood and from that work I was able to activate the pump and the vacuum controller through the module connector. The wires are the same color on the connector as on the pump as the harness goes directly between the two pieces. In any case, the relay looked perfect and contacts were not carbonized and the rest of the module (two PC boards) looked clean and no burnt smell in it or failed solder joints or broken traces. Looks like a robust unit. No wonder it fails infrequently.

I was able to repair my turn signal stalk without removing it. The wore broke right at the end of plastic and I had very little to work with, but I was able to strip about 1/16" of insulation on either side and solder them together. I also put a piece of shrink tubing on the joint. It's not a pretty fix, but it works and if it fails again, I will remove the stalk and to a better job of it. I did not feel the need to buy new stalk at $150 or so for one broken wire.
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Vladimir. '98 S70 base, 5-speed manual - his, '93 945 - hers