Skyjack electric scissor lifts (MC labeled units) and vertical mast units (SJ12 & SJ16) both use a Motor Controller to regulate the speed of functions. These Motor Controller equipped models use the same pump motor contactor as the models without a Motor Controller, but with one important difference: the Motor Controller units require a suppression, or flyback diode between the coil terminals on the contactor.

The diode is placed between the power wire (19A) and ground wire (02). This diode prevents the voltage created when the contactor coil collapses from feeding back and damaging the Motor Controller.

The diode is shown between the power (19A) and ground (02) wires at the contactor coil terminals. See Figure 1.

Original equipment diodes have a + and – sign molded into the diode body as shown. If you are using a replacement diode, Part #102921, make sure the silver stripe on the diode is facing wire 19A. The contactor replacement part number is #165865. It will arrive with a new diode installed, but always make sure the diode is installed on all Motor Controller units.

If you have any questions regarding this part or anything regarding your Skyjack product, please contact Skyjack Product Support at 1-800-275-9522 or email service@skyjack.com.