ColoradoXJ

My fan is continuously turning on and off every 5 seconds or so. doesn't matter if the engine temp is 40 deg. or 200 deg. I already tried a new relay to no avail. HELP!!! IT'S ANNOYING!!!

djb383

If the vent selector is on defrost/defog or a/c, the a/c compressor engages thus turning on the electric rad fan. Sounds like freon is low thus rapid cycling.

pa96xj

wire it to a toggle switch then turn it off and on as you want.

RenoXJ

Mine does that too, when the defrost is on.. because defrost uses the AC compressor.

Soldat

Is there any way to stop that? It's so annoying when I just want my defrost and feet blowers on, I have my engine rev up once every 10 seconds when idling making my jeep lunge forward a little.

djb383

Check your a/c freon charge. Being low on freon will cause the a/c compressor to cycle on/off rapidly, thus turning the electric rad fan on/off rapidly.

YellowSub2000

Rapid cycling of the AC Compressor will also cause the RPMs to surge a little bit because of the extra load. Def. check freon, or disconnect the wire going to the AC Compressor. This powers the clutch on the compressor. Remove the power and the clutch cannot engage, preventing the Compressor from cycling.

YellowSub2000

Or you can drive down here to South Florida and I can check it for you. Just bring freon.

98 JeepJeep

Good way to melt something.....