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Q: 40 amp fuse blows when trying to start the vehicle.

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When I try to start my escalade the 40 amp IGN A fuse blows. I think it is the ignition switch. It is NOT the starter, as I have removed the starter and had it bench tested at o reilly and they said it tested good. What else could it be??

My car has 187000 miles.
My car has an automatic transmission.

You have a short in this circuit or a fault that is drawing excessive current. It could be the coil packs, ignition module, or a wiring fault (a short perhaps). This will require some effort with a volt meter to determine where the fault is occurring. If you would like some diagnostic assistance, I would recommend having a mobile, professional mechanic, such as one from YourMechanic, perform an inspection for any electrical problems.

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