I recently bought a new Autopilot DIG-220 to replace an old one that died. I'm installing the new one, and step 3 of the instructions says to loosen the thumbscrews of the unit cover, slide off the outer housing, and disconnect the 3 plugs that connect to the display mounted inside the cover. My new unit only has 2 plugs connected to the display. Is this a typo in the instructions or am I missing a plug? Thanks