Replaced stereo in truck, now my truck wont start?

I replaced my factory stereo in my chevy s10 with a aftermarket pioneer radio, it can with its on harness and wiring adapters specifically for my truck, i butt spliced all the wires and hooked it up. I unplugged the negative from my battery and everything but nothing worked after. no radio, no lights, no truck. i put the old stereo back in but nothing changed. I tried jump starting my truck but my battery tester says my battery is fine. please help

You don’t say what year truck this is, but you may consider the manual under “Security System”.
The system may be in “Theft Mode” now.

Or while contorting yourself to install the radio, you knocked a wire loose for the ignition.


Recheck the battery terminals.

Your truck has those side mount GM battery terminals.

Which I hate.


its a 1999 chevy s10 the radio did say theft proof but no red light or warning ever came on or does light up to show its locked?

IIRC, the factory radio came with a code to prevent radio theft, but this has nothing to do with the truck not starting. No light, no nothing points to a problem with the battery connections. Like @Tester said, recheck the battery connections with the side posts, both positive and negative. I also detest those side post setups. They’ve given me lots of grief everytime I’ve had to deal with them.

I had to clean the battery terminals and clamps on my 2000 S-10 Blazer on a regular basis. Is the underhoood light coming on when the battery is connected? If not, try wiggling the cables to establish a connection.

Ed B.