How do I disable the security system in a 99 sierra - Hello all, I am new to the forum and was wondering if anyone know how to fix a ...

Hello all,
I am new to the forum and was wondering if anyone know how to fix a 99 sierra that has a security light that comes on and my truck wont start?

Did you buy the truck new or just pick it up by chance?

I purchased the truck last may. It only had 50K on it and was in nice shape. There is an aftermarket remote start (I think)under the dash with relays but there is no name or # on the unit I can find. I was hoping adding a new remote start unit to the truck might be able to override the factory security system. Problem is the truck will leave me stranded and there is no warning sign. Sometimes if i use a different key it will start. Other times I have to let it sit for hours before it will start.

There is some type of mod between the remote start and the key cylinder to trick the vatts into thinking the key is in the truck while remote starting. If it is going bad it will throw the truck for a loop and not let it start. You could swing by any good Stereo shop and have them check it or just remove it.

Thanks for your help. I have an appointment at the stereo shop Monday morning too have the old unit removed and a new unit installed. i think the ignition is going to need replaced also but they are going to look at that on Monday also. Thanks again!

Good luck and hope all turns out for you. The ignition should be ok as they just have to tag a few wires for the alarm.