Tow vehicle battery dies

[JimM75]

We have a 2021 Fleetwood Flair 29m. We tow a 2020 Chevy Equinox premier 4 down. Apparently per Fleetwood the RV is set up to trickle charge the car battery while towing. We follow the owners manual as to what to do prior to towing. Trying to figure out why the car battery is dead upon destination arrival? We suspect it could be a fuse or perhaps the RV relay switch located underneath the top RV step? If it is a fuse no idea which one it is? Diagram does not specify. Car battery was new the end of June. Prior to towing put the car in neutral, foot off the brake and shut off. Aux light is on and the ding ding supposed to last 30 minutes. Any one have the same experience or can offer a solution?

 

[STCap]

How many wires is your wiring harness between your coach and toad? Typically you will need five or six wires; one of the wires goes to the battery of the toad.