Starter won't stop cranking

[targethead]

I have a 1985 K5 Blazer. It has been sitting and the battery went dead, so I was trying to jump it yesterday. When I turn on the ignition switch, everthing seems fine. I get power and the dash lights come on. However, when I turn the key to the start position and the starter begins to crank, it won't stop cranking when I let go of the key and it returns to the on position. I then turn the key back to the off position and the starter continues to crank. I have to take off the jumper cables to get it to die. Any ideas what might be causing this?

[Mikado14]

You have low voltage. Voltage and current are inversely related. So, if the voltage is low the current draw will be higher. This higher current can cause the solenoid contacts to stick. Hit it with a hammer and CHARGE the battery to full voltage and clean your terminals. Then try it.

[targethead]

Thanks. I'll give that a try. I appreciate you taking the time to reply.

[Gooseneck]

I agree with Mikado14, but once you do your trouble shooting and your confident that your solenoid is at fault, you should go ahead and replace the starter. Once the contacts stick in the solenoid they will most likely continue to give you trouble.