exhaust fan cycling when system should be idle

[Supertrooper1]

So I installed my nest thermostat. as soon as I turn the breaker back on the exhaust fan Cycles on and off on and off on and off. everything worked before on old digital thermostat. I'm trying to find a work around. please help.

[Patrick_Caezza]

@Supertrooper1 

Post a picture of the original thermostat's wiring here

[Supertrooper1]

@Patrick_Caezza  

picture 

 

 

[Patrick_Caezza]

@Supertrooper1 

Post a picture of the Nest thermostat's wiring if you have it.

Your original thermostat's wiring is strange.  The black wire appears to be a C wire yet the original thermostat doesn't have a C terminal.

Have you tried wiring the Nest like this?

Red - R to R (jumper to Rc not needed)

Yellow - Y to Y

Black - Not Used to C

White - W to W

Green G to G

[Supertrooper1]

@Patrick_Caezza 

I have tried both with the black on C and not hooking the black at all.  Both ways the exhast fan continues to cycle. And.. thank you for taking a moment for me.

[Patrick_Caezza]

@Supertrooper1 

Do this to upload a picture,

[Supertrooper1]

@Patrick_Caezza 

having trouble adding a picture. please advise how to add picture or send directly.