On some models, there is a switch mounted in the pallet grab area that is mounted to the platform. You will have to remove the 2 allen bolts and drop down the pallet grab assembly to get access. However, when you do that, it relieves the cable tension so you can't test the actuation process of the switch. Just test the switch to make sure it works with a VOM and if it don't, replace it. Then hold the assembly back up with your hands and have someone actuate the pallet grab to listen to the switch actuate. If you want to definitely see if this is it, bypass the switch temporarily to see if it fixes your problem. Be careful, because I can't remember if it is a NO or a NC switch that is held open. Check to see which contacts have wires on them and check to see how it is actuated, then make the appropriate bypass either with a jumper cable or just disconnecting the switch. Chances are, this is the problem if you have a message that says "No Pallet."