I have a 1997 Silverado
starts just fine , idles just fine , as soon as you step on the brake to put it in gear it stalls , checked vacuum leaks , none. so while it was idling I was playing with the switchs , I noticed when you turn the head lights on it would stall, stepped on the brake with out trying to put it gear , and it stalled. removes the ABS relay it continued to idle, but had no power brakes. replaced the ABS relay. it stalled again when stepped on the brake. so it appears anything to with lights makes it stall. all fuses are good, all relays are good, wiring looks fine no burns or anything. in fact everything functions as it should , until you step on the brake or turn on the headlights. headlight switch is also new. don't know if this is relavent , but courtesy lights inside the cab has never worked . cluster lights works as they should.
anyone know what the problem , I would be grateful for the help on fixing this, Thanks in advance.