I don't think you'd have a bad hot surface light, it's on , so it works.

If all your sensor circuits are correct, sounds like it from your reply, you need to start looking for a shorted wire on the sensor circuit to chassis ground. We're completing a circuit some where in order to turn the light on.

The Way this works is;
You have 120 VAC on the wire to the 1B terminal, Tan wire,
You have 120 VAC on the wire to the 2B terminal, Black wire(s),
at the terminals on the sensor.

When the sensor circuit reaches temp. and closes, it causes the 240 VAC to travel to the hot surface light, and it illuminates, until the temperature cools down , the circuit opens and the light goes out.

Though, I have never had this problem, there is a possibility that your bad infinite switch, could be the culprit,

Replace the bad switch, if the light still remains on, you'll need to start looking for a shorted wire.

Let us know what you find.

Good Luck,

:) :) :)

Bottom line, my problem is solved. I decided to buy the Infinite Switch as Joe M. from the APP tem suggested earlier. I installed this morning and the custom burner works again. Taking my time to ensure that I do not brake anything else in the process of doing it, the installation took about 30 minutes.

Here is how I did it on my electric range Jenn-Air JES9900BAS:
1. Turned power off at the Circuit Breaker.
2. Removed Oven door. (Opened door about 20 degrees and lifted it up)
3. Removed 4 hex screws from the control panel. It requires a 1/4 in socket. These 4 screws are visible after you open/remove the Oven door. (There are other Philips stainless steel (SS) screws holding the SS panel clad. I did not need to remove them)
4. I installed one of the oven racks at the highest setting with a 4 inch cardboard box on it (for extra height) to allow me to put down the control panel once all screws are removed. (Thanks for the pointer Joe M.)
5. Holding on to the panel, (so it does not drop by itself) I removed the last 2 side screws from the control panel. (One Philips head screw on each side of the panel) Gently I guided it down and out and put the control panel on the cardboard box.
6. Before I removed the connectors to the switch, I looked and noted how far they were seated in. I also noted the color and orientation of each connector. Removed the connectors to the infinite switch. It is a good idea to take a digital picture before removing the connectors. (It seemed to me that it would be hard to reverse the connectors, however, better safe than sorry.)
7. Removed the front right knob and the 2 Philips screws, behind the knob, holding the infinite switch. Removed the old infinite switch.
8. Reversing the process, I installed the new switch by using the 2 Philips screws from step 7, and reconnecting the 2 electric connectors from step 6. Make sure the connectors are properly seated in the back of the infinite switch.
9. Re-installed the control panel using the 2 side screw from step 5 and then the 4 screws from step 3.
10. Carefully, not to drop it, I reinstalled the Oven door and closed it.
11. After, checking again to make sure that everything was reinstalled and my electric range was the same way it was before I started the job, I proceeded to turn the power back on.

Total success. The custom dual element worked again like when it was brand new.

I would like to thank Joe M from the APP team, again, for his invaluable coaching and help.