Tahoe won't crank
My 03 tahoe has quit starting it
won't even turn over I can put a
jump wire on the starter relay and
it will turn over but still won't start.
Note the diagram for starter. Make sure battery has a full charge and connections all good. If you jump the switch side of starter relay, right side in the diagram, it's that line with arrowhead, the starter motor should crank the engine. In that case, you would check control side of starter relay, left side in diagram, that side needs voltage and ground. The top wire on that side, in diagram, is voltage. The bottom wire is ground. You can see that upper fuse, goes hot with key on and is wired through the neutral switch then to control side of relay. You can see crank fuse, lower down, The crank position of ignition switch sends voltage to crank fuse then to pcm, telling the pcm to ground control side of relay. Engine cranking, key on, check for spark at the plugs--proper fuel pressure and fuel injector pulse. Any applicable trouble codes? Is your security lamp turned on? Sorry for the long post, just trying to be through. good luck.
My be the security light. Try closing all doors.. turn off everything. Turn key forward ,not start it.. but leave it forward.. for about 20 min. Or untill light goes off dash ..security light. Then wait 20 seconds and start it