""why is that if the diode pack or the regulater within the altenator has failed short circit it is possible for the altenator to back feed the warning lamp circit therfore keeping the warning lamp on with ignition off there for engine stays running with ignition off"" The warning lamp circut isn't conecteted to alternator on this model it goes to engine control module then by can to cim.Have a look at diagram on autodata.