clicking sound

Back area? Behind the engine or in the rear of the van? Does it have a rear air control for passengers? Maybe the fan motor is stuck and the circuit keeps trying?

Sorry, I should have clarified better. The rear of the van. Yes, it does have rear air control for passengers. It is the Touring version of the T&C. All the bells and whistles!! I seem to hear it most in conjunction with the AC cycling on and off but can't pinpoint where it is coming from. I have sat in and ridden in and moved around the back part of the van and still can't exactly pinpoint the location and/or ceiling vent it might be coming from.

I'm not thoroughly familiar with the a/c on this brand, but typically rear air has it's own pressure switch and flow regulating mechanism, one or both of which may be electrical. It could be cycling on and off relative to the passenger's demands for cold air or your system could be a little low on refrigerant. Put a gauge on the vacuum side to see if it's within proper range. If you don't know what I am talking about, either YouTube how air conditioning systems work or take it to a shop.