I found out today there are still parts on my 1998 Ram that I have had no interaction with.

What is this called, what does it do, and should it be clicking repeatedly non stop?

It's on the passenger side inner fender just under the A/C line.

 

That is the EVAP purge solenoid. It should not be clicking constantly but wont really hurt anything. I wouldnt worry about it until. It throws a cel.

 

What kind of issue would it cause when the A/C system is in use...if any?

I'll get another one ordered and plan to replace it.

 

Its apart of the EVAP system...nothing at all to do with A/C. If the solenoid is not working properly it will set a CEL. I wouldn't worry about it until this happens.

 

Fair enough, but the clicking is loud enough to be heard in the cab, and it's annoying. Assuming it's not supposed to click all the time, I may replace it simply for that reason alone...that's it's doing something it's not supposed to do and it's loud enough to be annoying.

 

it should only click a little at the times the evap system decides to test or purge the system. it should not click all the time.

they're not expensive. autozone has them for $30-40. rockauto and internet would be considerable cheaper.