Hey Joe, These JetCat valves are probably okay on the 7.4 HV, but may get fried if you turn on the HV at its 8.4V right off the charger. That being said you can’t do what you are trying to do without an add on RC controlled switch (HK etc.) as these units are not set up like a servo even though the wiring makes them appear as if they operate in that fashion. They are current onpen, current off:closed as I recall. The presence of the third wire is misleading. Mel maidened an Xcalibur on his own today! Wish I’d been there to see it!
Aloha,
Len