If my battery connectors are loose will my truck idle lower than normal?

 

I'm going to assume that this isn't a hypothetical situation. Why don't you just try tightening the connectors first? It seems easier than creating a thread about it and then having to wait until someone gives you an answer.

If you tighten it and it doesn't fix it, then come back and tell us the symptoms. It could be a number of things...

EDIT: To clarify, it could be a possibility.

 

I would have tightend then but they were all the way tightend so I bought new ones put em on and it idles a little high than it used to

 

We need more info if you really want help. Year and details of truck engine,year,miles, whats done to the truck that's not stock. Ie ignition, k&n maybe over oiled, ect. Not just a vague simple question. Not trying to be a D but just saying read a few other help threads and you will see the common info that usually helps. And pictures always help and btw get people to look at your thread.