Been having this problem for a while and having trouble tracking it down.
I have replaced all relays and fuses, replaced the starter with a brand new one (Not a reman).
The truck is trying to start its self when the keys not even in ignition. When I put it in reverse or drive it stops, but as soon as I go back to park/neutral it starts again.
I have no idea where to start to trouble shoot.
It does have a remote start system that was installed before I bought the truck in 2009, but hasn’t been used as I never got the remote with it.
Any help/ suggestions is very much appreciated.

 

Welcome to chevy - please post your vehicle details for us - year/motor/model etc

 

When its doing that, pull the starter relay to see if it stops. Then with a test light see which terminals have power, should be just one, with key off.

 

It’s a 2000 Chevy Silverado 1500 5.3

 

It stops when I pull relay, comes right back on when I reinstall the relay. I’m at work right now but I will test the terminals when I get off.

 

So there's power activating the relay when it shouldn't be. If so then that's the circuit that need to be checked out.

 

Pin 30 and 85 have power with key off

 

Pin 30 is constant 12 volts from the battery. Pin 85 is 12 volts switched, like when the key is in the start position. So the wire 85 pin has 12 volts going to it with key off. One way to find issue is to install a test light on on pin 85 and pull fuses until the light go's off, then find out why that wire is getting 12 volts with key off. On some trucks the power box, where all fuses and relays are, has shafted wires and such, so remove the screws holding the box to inner fender and flipping it over to check for any degraded wires. At that time confirm the wire color for pin 85 and trace it out.

 

I removed all ign fuses and still had power. I’ll remove the box to trace the wire now.

 

I removed some after market lights I had someone install and I don’t know if that had anything to do with it but I’m not having the issue any more. I’ll give it a couple days to see if it does it again and then I’ll come back to this thread. Thanks for the help and the intention to walk me through it.