Runs full speed without pushing the pedal!!!

I believe this machine can operate without the foot pedal attached. Disconnect the foot pedal and try using Start/Stop button. If same symptoms with pedal detached then likely problem is speed control module inside machine.

Does light come on. Still could be bad cord replace.

You don't say whether your machine is newer or an antique. The model number would really help your helpers help you.

Let's work on your vocabulary a bit: A presser foot, is what holds the material down so the feed dogs and move it through the machine. The foot pedal is pressed to make the machine go. ;)

However this sounds like a machine that needs service... by your explanation of how you change the speed to fast and run it fast... it sounds like one of the modern electronic machines. Since modern machines don't have oiling and greasing guidelines I suspect your machine I well overdue for servicing. Find your local sewing machine tech and take it in. Ask for a "Clean, Oil and adjust timing" and be sure to mention the motor issue. While he's there ask him to check the belts and replace if necessary.

Good luck.

the foot pedal would have to be check at a sewing machine shop & they
could tell you more about weather it would be easy to fix or not

Unplug the foot pedal to see if it still runs fast. If so, there is probably an interior defect related to motor control that will need to be serviced. If everything is quiet when the pedal is removed, then the foot control to the speed rheostat is loose or broken. Hope this helps!

The carbons in the ceramic tube normally break away, you should not have any problem if you have a new foot control,

Undo the foot control and take out the small square suppressor and throw it away, you don't need it anymore.

well particular on electrical problem foot control is a switch of motor that deliver speed varies on how you press the foot pedal it consist of circular thick plate carbon the old model and the new one electronically control of power ic,It depend on how this pedal was contro.Anyway besure the power is off or unplug the machine; this control was been connected in series connection to the motor which you can test if your foot pedal control is defective. Disconnect the line wire holding foot pedal from the terminal inside motor assembly.If your not qualified electrician don.t do this.Connect the two terminal wire that inside the machine where the motor mounted.This connection is supplying your motor in full speed,Declucth your machine from the handwheel so that the motor run only.Plug the machine and switcn but you must jug only if the motor run in couple second of course without the foot control this was disconnected already.So your foot control is defective vice versa if motor does not run without foot control motor is busted.
how to fix if foot contol is defective, in carbon type you must replcace the circular thick carbon.On Electronic control check the IC if this open or some capacitor and resistor are open,Replaced any pars that had been short circuited.If the motor is defective replaced the carbon brush mounted at two side of motor case,There is an opening port.The carbon brush has spring holding push this carbon brush to the brush armature of rotor.

sounds like the contact in the foot peddle has failed try a new peddle