A friend of mine has a 99 V6 it just recently started stalling on him at odd times like driving on the freeway? He took it to some hole in the wall garage and so far they have replaced the fuel filter fuel pump battery connections, checked battery etc. It still does it? when it starts to do whatever its doing all the service lights come on. No codes are present? Would an aftermarket alarm have anything to do with it? I'm thinking maybe altenator or relay switch but i'm not very good with the V6 vehicles.