It sounds like you installed it after the 't'-fitting.  It would have to
be installed between the regulator and the 't'-fitting to be able to use
both appliances at the same time.

Maybe I shouldn't have called it a "T" fitting. The fitting in the kit has two connections on it-one for the short hose that connects to the 1lb bottle and another one for the longer hose which is for connecting to a BBQ grill. The only logical place I could see to install this is between the on/off valve and the regulator. It's tight in there, unlike say on a travel trailer or large RV which is what this thing is intended for, I believe. I've had requests for pics, so later on today I'll post pics of the install.     Jeff