One could gues that wireguidance wasn't given priority due to the fact that old torpedo types could do the job of sinking enemy merchant ships. Wireguidence would have given them higher chanches of geting the trublesome ecortships killed.
But killing escortships was not the objective of the uboat force.?
Still an functioning wireguided torpedoe early in the war would have donne a great difrence. But later on in the war allied code cracking and aiborne radar would have decreased the importance of the wire guided torpedoes.

I'm still intrested of any online source for early wireguided torpedoes.

/Johan Fredin