What's wrong with my Buick? It won't turn over.

It's a electrical problem as when you turn the key nothing happens so first thing is get a multimeter and check the starter motor has power when you go to start the engine , check both terminals to and from the battery good luck colin

Turn signal plug should have nothing to do with it not starting. Disconnect the battery for 10 to 15 minutes. Then try again with the key.
When you jumped the solenoid, it would start because the key may have not been in the run position. So the Security light was on, and did not energize the fuel pump.

Disconnect the battery as stated.

check connection and wires at battery for damage or corrosion if good check for power to ignition switch if no power check for damaged or shorted wiring if good turn key and check if power going to relays or accessory's at fuse panel if no power switch may be bad

It sounds like you blew fuses other than just the main fuse. Hooking the battery up wrong can destroy major components as well, like the starter, battery, Computer, moduals. You might need a good shop....

Is the security light on or blinking?If not then do you have power to the starter.You can check this with a test light.You should have power when you turn the key to start.The test light should light up.Should be the small wire.I believe it is purple in color.If the security light is on then you will have to get the codes to see what is causing the no start.Hope this helps.Good luck.

The starter is where the engine joins the gearbox, usually on the engine side. Check that he wiring it connected at the starter and the ingnition switch. Make sure the battery terminals are good and clean and tight. Otherwise the starter solinoid may be faulty, or the starter itself.

either battery is dead or starter fuseable link is blown

Check the battery connections and clean. replace bolts.

Check all battery connections for corossion, battery to motor and battery to body ground for corossion under mounting bolts. Also check motor to body ground strap. Also check battery wire and all otherwires on starter solonoid. Check condition of battery, even if the dashboard lights up your battery can not have enough juice to turn car over to start.

If you get power to the small wire on the solenoid, when you turn the key to the starting position, the ignition switch is ok and you may have a bad solenoid and/or starter. Most parts stores can test your starter. Also check the "crank" fuse and ignition fuses.