I don't know where the connector is located in the wagon but it will have 2 pins with a black/red/white wire and a brown wire on one half and 2 black/red/white wires and 2 brown wires on the other half of the connector. The connector acts as a splice or Y to connect the 2 pumps so it would be a convenient spot to check without having to get underneath if you can find it without ripping up the carpet.
I'll check to see if I have any info on where it is located. It is labled as X36/3.