2005 GMC Sierra when i put in the accessory position to wait for glow plug indicator

markie1961

When i try to start truck and put it in the accessory position on ignition it tries to start instead of being in accessory position. Is the starter going bad? Battery?

Mr_Shiftright

Sounds like the ignition switch is sending a start signal to the starter when it shouldn't be---or maybe there is a voltage leak into that same circuit. You may have to back-probe the problem all the way from the starter solenoid/relay back through the harness to the ignition switch. I suppose even the fuse box could be shorting out.

These types of problems can be tricky. I don't think starter or battery is the issue, based on what you described.

It sounds like you are using the wrong terminology--the "accessory" position is when you turn the key toward the driver; the first click toward the dashboard is the "ON/RUN" position and the last, spring-loaded position is the START position. So it sounds like the car tries to start when it's only in the ON/RUN position.