Here is the wiring diagram
http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%208576801.pdf[COLOR="Blue"]
Dryer vents through roof, and vent was cleaned last year.[/COLOR]
I would not assume that the vent is still OK as this is the most common cause of your symptoms.
Undo the dryer from the exhaust
Run a load
If the load dries correctly then you have a vent problem.
Clean/check the vent system. Make sure the outside louvers/vent open fully/clear.
If you do not want lint in the house.
Take a pair of pantyhose, put one leg into the other and attach this to the dryer exhaust.
Leave enough room behind the dryer so it can blow out like a windsock.
Run a load.
Both the above will allow you to check the air flow and temp.
Also the above is NOT recommended for a gas dryer due to possible carbon monoxide problems.
[COLOR="Blue"]I did not want to throw money at parts without at least a better idea of what is the more likely issue - thermal limiter or thermostat.[/COLOR]
Could be either also may be a grounded element, where only part of the element is heating very hot so the unit cycles too often. Or the element may be running on 120 volts instead of the full 240.
It is unusual but not unheard of for a thermostat, thermal limiter to start switching off at a lower temperature.
Also your thermostat has an internal heater perhaps it is being held on all the time, this would keep the unit in low heat mode. Try different heat settings to see if it makes any difference.
Check the heating coil.
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 10 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 you do not own a meter, I would suggest you purchase a one. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.
There is a good STICKY at the start of this forum about it's use.
