Glad you got it figured out. Assuming it was one of those two pin JST connectors that messed you up…
There does not seem to be a standard as to which pin gets the red wire. I’ve purchased them wired both ways. Of you have patience, the pins can be released from the plastic housing so you can correct the polarity. Or, just cross wire them and be done!
For the sound, if you power the board from the battery at all times, it will idle for an extended (very long) time when running track power and the engine is stopped. In order for the speed to follow, the speed input needs to be connected to the output of your Revo or the track depending on switch position. I believe my diagram near the top of this thread shows how that is done.
BTW - If you need a source for these, Ric Isard is still in business and sells them in bundles with silicone insulated wire (very pliable) for a good price. He now does business as https://www.midwestbatteries.com/?fbclid=IwAR2Ok_ZeydFH55eLuVNcw40qIJljhLvzDaFUFhDaKjS-0bAGVUO6_f_Xh1I and sells through Facebook Groups. I have no idea why he doesn’t post here. I guess he’s afraid of feedback from dropping his RC line.