I have a jenn aire electric cooktop. The fan when the burners are on quit working is this a hazard?

SOURCE: knob not working and some burners not heating

The switch under that knob is bad.  It's called an infinite switch.  As far as the elements go, first thing to check is for proper voltage (220) to the cooktop.  Let me know what you find.

SOURCE: jenn-air downdraft fan not working

there are 4 wires for that red white black and green sure you didnt miss a wire

SOURCE: Jenn-Air Gas Cooktop Model CVGX2423

Just had this problem today on our seven or eight year old Jenn-Air cooktop. When using the front right burner all ignitors would continue to fire until I turned off the burner. The three other burners worked correctly. After trying all the obvious soulutions w/o success I pulled off that burners control knob and the rubber seal which exposed the valve. Their was a bunch of crud in there. I put a small (one inch) paint brush in there and vigorusly loosened all the crud. I then inserted the nozzle of our central vac - which just happened to fit perfectly - and sucked all the stuff out. I repeated the proceedure a couple more times, reassembled the knob and started the burner. Worked just perfectly!!! YMMV. Good luck.

SOURCE: Jenn-Air electric stove top - burners/fan won't come on

I had the same problem. Went to an appliance store that carries Jenn Air. Replaced both plug in units. Now they work perfectly and it cost less than $350 total! Good Luck!

SOURCE: Electric ignitor does not work at all on Jenn-Air Gas cooktop

need to replace the ignition coil.no adjusment the unit is power operated 1st check the plug,outlet or main swicth sometimes not properlly connected.