i have no power to the ignition switch or to the starter i put a test light to them. battery is 3 mos old and the truck runs great but this started after i had a new tranny put in. sometimes i could play with it 4 a few mins and it it would go but now it wond
The two plugs on the transmission range sensor/neutral safety switch, located on the left or drivers side of the tranny, tend to get hot and deform on these trucks. If they stick and are forced apart when the tranny is removed this is what usually happens. Check the condition of these plugs and the pins in the sensor itself for damage and clean/repair/replace as/if nessesary. Also, the electrical side of the ignition switch is prone to failure but if it lacks input power this is probably not the case. If you have not, check every fuse in both the underhood and dash boxes, particularly the ":trans": fuse, physically looking to see if there is one blown. I have seen power ":feed back": down a circuit and light both sides of a blown fuse on these trucks, fooling a tester or test light. One last thought, if you turn the key on, without trying to start the engine, and the security light is blinking, wait 600 seconds(10 minutes) for the light to stop blinking and try again to start the engine. 600 seconds is the GM security relearn interval and it may take as many as three tries to learn. Good luck and happy motoring.
Need more information,
Set you’re parking brake and try slightly moving the gear shaft to neutral or ":wiggling": it in park WHILE TRYING TO START THE TRUCK, if the neutral safety switch is not adjusted properly, you will have trouble with the engine turning over to start.
Do you hear any kind of noise as in a click when you turn the key to the start position?
if you are hearing the click and it won’t turn over then it is the starter.
make sure you have a good ground they may have left ground loose check fusable link on power side trace power from battery to were you lose it with your test light repair open circuit if you find out were it is lost
I agree with James – sounds like a ground issue.
try to reconnect the wires that go to the nuetral safety switch on the transmission
your starter motor is ratshit or has a loose wire running to it.