Keep Dust and Water Off the Relay Terminals The intake heater relay sits low in the engine bay where road spray, oil mist and dust collect. This DZ93189583513 cover caps the relay box and its wiring, so terminals stay dry and the connection does not corrode into a cold start fault. Fitting behaviour Clips onto the standard mounting points, no drilling or modification. Removes in seconds for relay access during engine bay work. Direct replacement for the original part number.