If you look at the right track near the exit, you will see a black rubber bumper. Mounted to the machine, there are some brackets that are called track stays that basically prevent the machine from flipping over if someone were to hit it because they would grab the bottom of the angle of the track. On that bracket, you will see a weldment that sticks out. When parked at home position, how far is the weldment that sticks out from the bumper? If it's more than 1/2" or so, that could be contributing.
The primary components to the start of the wash are the position of the bayplate, the position of the backup airswitch and the tire photoeyes (behind the wheel scrubs). Installed according to print, everything will be sequential, and it’s not possible for a customer to make two of those devices blocked or detecting the car at the same time. A customer would drive in and get on the bayplate. Once they leave the bayplate, they would next block or pulse the backup switch (air or tape). After that, they would block the tire finder photoeyes (placed mid-machine just before the wheel scrub). If a car were to just drive through the bay, the machine would see a pulse of each sequentially. The reason it’s important that it be sequential and not more than one at a time is so we know that we don’t have the vehicle with the rear tire on the bayplate which can cause issues.
In a normal wash, the customer arms the machine and as they get onto the bayplate, only the bayplate will get blocked. Once in position for 2 seconds, the wash cycle begins.
If the customer goes a little too far, they could pulse the bayplate then pulse the backup switch. If they just backup at that point, the backup switch would pulse again as they drive reverse and the machine would start after they get back on the bayplate.
If the customer pulls even further forward , they would pulse the bayplate, pulse the backup switch, then block or pulse the tire photoeye. The machine will tell them to backup. If they do, they would pulse or clear the photoeye, pulse the backup switch, then get on the bayplate. The machine would then start.
If everything is installed in correct positioning, all above will happen and the machine should run properly. Where we run into problems is where something is out of position which could allow two of the components to be blocked at the same time. As an example:
If the backup switch is installed correctly but the machine doesn’t go all the way home up against the bumpers, this allows the photoeyes to be further towards the rear (entrance) than expected. Even if only a few inches away, it moves the machine close enough where a customer could block the backup switch at the same time they are blocking the tire photoeyes. As a customer backs up, they may not detect the pulses individually and in order so it will
lock out the bayplate. Same can happen if the backup airswitch is loose and if the hose drifts closer to the tire photoeye.
Effectively, the same thing can happen if your backup airswitch isn’t always detecting (the box on the wall where the switch is at getting full of water and shorting the switch). If this happens, we see the signals going in proper order when the driver is pulling forward, but if we start to go reverse and miss that backup pulse and then we just see the bayplate signal, that is effectively the same as someone pulling forward. We detect it that way and react like the rear tires are on the bayplate so we
lock it out. Only way to recover is to reset the machine.
