Looks like half the coil is shorted out by the Aux switch. This will cause high curent to pull the contactor in. After the contactor is pulls in the Aux Switch opens removing the shorted portion of the coil. The current is now reduced to half of the pull in current, and is refered to as Holding current. To verify this measure the resistance of the coil with the contactor open , then manualy press the contactor armature down and observe the coil resistance it should increase.