Sorry but cannot be very helpful
I did find a manual for this series but it was pretty pathetic and did not include any wiring diagrams.

Have you looked in the control console often they store diagrams in there.

Here is a a manual which does not include your unit but may at least give you some insight as to how Amana tends to wire units.
http://appliancejunk.com/forums/index.php?action=downloads;sa=view;down=404

First thing to check with heat problems is the power (only applies to electric unit)
Try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker.
Check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
Do this with the heater off and on.
[COLOR="Red"]Be careful as 240 volts is lethal !!![/COLOR]