Ralph Morgan Posted July 5, 2002 Share Posted July 5, 2002 Making final electrical connections on the Zetec installation (in live axle 4 speed - replacing a 1700 Crossflow) I'm stuck on connections to the starter motor (equivalent to Halfords 407/Lucas LR146 from local parts factor). This has 3 terminals, whereas the old unit (and any others I've seen) only had 2. One connection is obviously the control feed to the solenoid, and the larger of the others for the power feed from the battery live terminal. What's the third one for? Initial thoughts are that it's a direct earth conection, to be linked to the battery negative (it has zero resistance to the starter body), but can anyone confirm this or give the correct answer? Link to comment Share on other sites More sharing options...
allen Posted July 5, 2002 Share Posted July 5, 2002 Ralph, One connection is not used - it goes live when the solenoid is energised - i.e. bridging both hefty terminals will start the motor without intervention of the solenoid. Allen Link to comment Share on other sites More sharing options...
felix.klauser Posted July 6, 2002 Share Posted July 6, 2002 In some applications there is a ballast resistor in the supply line to the coil. When the ignition key is turned the solenoid closes the circuit to the starter motor. This results in a voltage drop within the car which as far as the coil goes is compounded by the balast resistor so a second circuit is closed by the solenoid to supply battery voltage straight to the coil while cranking. Not needed for a Zetec and indeed most 7's I would have thought. Link to comment Share on other sites More sharing options...
Revin Kevin Posted July 8, 2002 Share Posted July 8, 2002 Ralph Save the hassle re install your proper engine. Revin Kevin Crossflow. Link to comment Share on other sites More sharing options...
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