I don't know what your 7 dollar wash consists of, but I have a few questions for you.
1 does the $7 wash have underbody?
2 does any other wash have underbody?
3 If other washes have underbody, are you experiencing the same timeout issus with them?
If the answers are yes to all three questions, I would say you have a problem with your underbody sensor system. It could be photo eyes, input output cards, amplifier, or relay. It could be as simple as adjusting the sensitivity.
I think what is happening,( I am assuming the answer to all three questions is yes), is that the time out is happening because the start of the wash package in this case comes from the underbody start, nat the wheel well switch.