Check for 24 volts at examination point TP10, if no voltage at TP10 after device has reached established position HTT is open. Good experience with Pelican, I really recommend, we get a completely new forty' HC container with all certification desired for export. This truck and trailer can in shape https://container-40ft-for-sale27157.arwebo.com/49678103/container-40ft-for-sale-for-dummies