View single post by Mark Rosenbaum
 Posted: 01-28-2006 02:58 pm
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Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
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 If your car doesn't have the battery junction, one would need to connect the brown wires to the main battery cable terminal on the starter solenoid.  You'd need three wires: two to the three-pin engine bay connector, and a third to the alternator.  It would be acceptable but not desirable to hook up the alternator to one of the brown wires on the engine side of this connector.  Obviously, if the alternator isn't connected properly, it isn't going to charge the battery. 

The second large terminal on the solenoid connects to the starter motor through a thick copper strap that protrudes from the starter.  When the solenoid is activated, current from the battery flows through it into the starter, then goes to ground through the starter's case.  The electricity runs through the chassis then through the negative battery cable and returns to the battery.

There will be two other terminals on the solenoid.  These are normally blade connectors, and yes, it does matter how they are connected.

One of these terminals activates the solenoid when +12 volts is applied to it, provided that the body of the solenoid is grounded through the body of the starter.  Solenoid operation is pretty noticeable, so you can determine which terminal does this is by momentarily applying +12 volts to each blade in turn.  The red-white wire should come from the ignition switch etc. and therefore will connect to whichever terminal activates the solenoid.. 

The second terminal provides voltage from the main battery cable when the solenoid is activated and the starter (hopefully) is cranking.  When this terminal is wired to the junction between ballast resistor and coil, it bypasses the ballast resistor during cranking only, so that the car will be more likely to start.  The white-yellow wire should connect to this terminal.

Unfortunately, the remaining wiring gets a bit complex due to federal 'safety' mandates.  The START position of the ignition switch connects to the Infamous Seat Belt Warning Module (ISBWM).  The module, in turn, connects to the Start Relay, and this relay, when energized, connects +12 volts to the red-white wire that runs to the solenoid.

Only the ignition switch and Start Relay are necessary.  The ISBWM can be bypassed by jumpering together pins 11 and 12 of the round connector that plugs into the device.  The entire system could also be removed entirely, and only the 'Fasten Belts' warning light would be disabled.  (If you elect to remove the wiring, note that there are two switches in one package attached to the underside of the parking brake handle; one connects to the ISBWM, the other to the 'Park Brake Fail' warning light.)

Other than the ISBWM, the system is quite conventional and normally very reliable.