You can tell if the GPs are working if, when you are in the pre-glow position (gorilla knob pulled out to just short of the start position) that the cabin and dash warning lights all dim (like in the old movies when the electric chair in the prison was used). The salt shaker can be left out of the circuit, if the GPs were updated to new style in parallel, it very well could have been, but the tell-tale sign is the dimming of the lights. The old "series" style GPs which the car came with would have required the shaker to be in series with them but the new style parallel ones would not. Basically the procedure is pull the knob out to the pre-glow position, count to 5 if it is warm out, count to 15 if it is cold out, and start. Use the idle control knob when it is cold out to keep the idle speed up.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz