Mike, Pat, we have a 2018 2552 and there was nothing behind the antifreeze coolant reservoir. I just installed it by removing the reservoir and connecting the Trik-L-Start unit as shown in the picture. Not sure if it should have been included by PC when the RV was built. Our engine battery was going dead within 3 weeks, when parked with shore power. I had contacted PC and they sent me the Trik-L-Start unit, with directions, which I connected as shown in the picture.
John D.