Legacy FEF3 2 cab light blinks and no smoke

Could be a loose connection. I had a similar problem on a diesel. I took the shell off. Removed the smoke unit opened it up and checked all the connections. I didn’t see any obvious issues. Put it back together and still working great. I’d check wiring connections. Does cab light blink if you turn off smoke unit?

After removing the shell on my bench, I noticed the fan was not turning. I loosened the heating element board and the fan started to run. I think I had a bind on the impeller. It seems to be working on my bench right now. However.....in removing the top off of the smoke unit I may have relocated the thermistor. I would like to put this thing back together. So................Will someone in the know please tell me the correct distance from the heating element that the thermistor should be located? Are we talking about the distance of 2 nickels or 1/4" or what. May need authorized techs to answer this one. Not sure. Also should the thermistor be above the batting or can it be into the batting? Thanks for any input