Let's ensure you're talking about the correct part. The cycling thermostat is on the BLOWER HOUSING beside the THERMAL FUSE. The Heater thermostat is at the bottom of the heater housing. In either case, both thermostats should be a CLOSED circuit. The operating thermostat will have FOUR wires. The two smaller terminals will read a few thousand ohms. The 1/4" terminals should be a closed circuit.
If your heat is cycling off too quickly, and since you had a blown thermal cutoff, I'd tell you to ENSURE your exhaust is clear and not pinched, blocked or restricted in any way. Also, make sure it's not too long with too many bends and or elbows. The hi limit stats don't generally blow unless there is an exhaust problem. Take the exhaust hose off the back of the dryer, turn the dryer on and feel the air flow. Reinstall the hose, turn the dryer on, walk outside to feel the air. Compare the flow. They should be very close in velocity.
The cycling t hemostat has two small and two larger terminals yes. Pulling off the larger terminals and measuring across, you should have a short circuit. Pulling off the smaller wires, you should read several thousand ohms.
The other thermostat things? The thermal fuse beside the cycling thermostat is obviously good, otherwise it wouldn't heat. The thermostat on the heater with the jumpers to the other one should have been replaced with the thermal cutoff. They are sold together in a kit. You NEVER replace one without the other. You should have purchased part 280010 which includes both.
I can tell you that the heat will cycle on and off. Does the heat ever come back on after it initially goes off?
no I let it run on timed hi heat for 20 minutes but it never came back on. I ordered the cut off online but the manual didn't say anything about changing anything else. So are you saying i should change the 2 thermostats that are linked by a jumper wire too?
Does the ignitor ever come back on but not ignite gas? I think we're getting off track here. Let me understand, you said you replaced the hi limit and cycling thermostat. Do you mean you replaced the thermostat with the four wires and the thermal FUSE? The fuse sits beside the cycling thermostat. When you said hi limit, I was assuming you meant the hi limit on the heater housing (the lower thermostat attached with the jumper is the hi limit, the one above it is the thermal cut off)
1. initial start up gas ignites and runs a bit. then cycles off 2. ignitor comes on in intervals but the gas never ignites. over a 10 -15 min period. so no gas?