Bruce, I got the voltage reducer from Joblot, it is a Dennis Carpenter item, sorry, I don't have the part number. I'm going from memory here so, that's always dangerous but, the wiper motor in my car is located behind, and at the top of, the instrument cluster, (I don't think the metal duct is in the way, as it is mounted on the firewall and below the wiper motor). It is fairly easy to get to with the instrument cluster removed. The wiper motor in my LZ works however, a previous owner had removed the OEM switch/control and rerouted a cable, that they installed in the throttle location on the dash. I located an OEM switch (got it from Merv Adkins, he advertised on the LZOC web site,
www.lzoc.org), that I will be installing. The OEM headlight switch in my car is still good, so I'm using it. I did install and NOS headlight dimmer switch. I don't know if this will help you but, here's a photo of the '39 LZ wiper set up, taken from the Ford Service Bulletins.
