Here are your parts
Replacement parts for WHIRLPOOL KEYS850LT2 29"electric Dryer | AppliancePartsPros.com

Here is the wiring diagram
http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%203406681.pdf

You said you had heat but did not have a running motor.
This points toward a motor problem.

You will see in the wiring diagram that the motor has a pair of centrifugal switches, they close when the motor gets close to full speed.
One of them switches in the heater, this ensures that the heater does not come on till there is air flow so you should not have heat if the switch is operating correctly when the motor does not turn.

The other switch, switches out the motor's start winding.
Perhaps for some reason these switches are being activated all the time and therefore you only have the run winding in circuit and the motor will not start. Though usually you will hear the motor buzzing.

Could be the motor is just jammed solid with lint or the mechanism that activates the switches is broken.

Also the only heater device that should effect the motor is the thermal fuse on the blower assembly (Item 6 in Section 3).

On your original problem
You have to find out what caused it to go.
Note: that sometimes they do just blow on their own but changing it without checking other things is a gamble.

Check the heating coil.
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 12 ohms.
Then check from each side of the coil to the case/frame, both should be infinite ohms (open). If not the coil may have sagged or broken and is touching the case. This can cause it to run on high and the thermostats cannot regulate it.

If the above is OK then you will also have to replace the hi-limit as it should have regulated the temperature so the fuse did not blow.

You still have to find out why it blew.
Check that the belt is OK.
Check the seals (drum etc) in the unit. The air is pulled over the heating coils, through the drum and pushed out the exhaust. So any large seal leak will pull in room air and the cycling thermostat on the blower will run the unit hot.
Check that the lint filter is not coated with fabric softener residue which greatly reduces air flow.
Check/clean your vent system.
Check/clean the blower wheel. In your case it may have been the motor problem which caused the fuse to blow.

If all OK you may want to replace the cycling thermostat as it's contacts may not be opening (welded shut).

First check the outlet to make sure you have 240VAC. Sometimes half of the breaker can trip, leaving one circuit still live. If you're getting the prope voltage to the dryer, I would check for a blown thermal fuse. If all the fuses, thermostats and the door switch are good, the timer or the motor will be the problem.

If the motor runs, I would check for a dislodged or broken belt.