install the jumper when you want continuous airflow. Have you tried goin from 'auto' to 'on' at the tstat first? That might give you ac speed air though.

 

sounds to me that its a speed increase only.
you must already have fan on (continuious)

 

moved per OP request

 

I forgot to mention the jumper would be installed across G and Y/Y2 on the furnace. Regarding my fan settings, the installation guide for my thermostat, a Honeywell RTH7500D-1007, has a couple of references to settings for the fan. In the advanced system setup for the thermostat, function 0170 has me select my system type. I have it set to "Heat only with fan: Gas, oil, or electric heat without central air conditioning." since I use evaporative (swamp) coolers in the summer. Also, in the main display screen, the "System" is set to "Heat" and the "Fan" is set to "Auto". The other choice for "Fan" is "On" so I wonder if it just boosts the fan motor rpm. I couldn't find any reference to the continuous fan airflow increase in the Service Facts section of my furnace documentation. I don't have any interest in experimenting with the jumper unless I have some assurance no harm will come of it.

 

You stated you have no ac. Don't connect the jumper. Connecting the jumper G term= fan, Y/Y2=cool stage 1 or cool stage 2 will energize fan on a call for cooling or energize cooling when tstat is set to fan on. Anyway don't do it.

 

I looked up the wiring diagram for your furnace and see the note 7 that you are referring to. The jumper will allow the fan to run at a higher speed when the stat is set to fan on. Depending on duct size this may be detrimental. Noisy, hi duct static pressure and higher operating cost for no real benefit. Your duct system is probably sized for heat only which requires less airflow.

 

Thank you so much for the replies. I live in a split-level home with the furnace in the lower level. When the furnace was replaced a number of years ago, I had the installer put another return in the bottom of the wall that is adjacent to the furnace. The thought was to ensure the furnace fan had all the air it needed and to create an airflow that allows the downstairs rooms to heat up quicker when needed for guests and family activities. In the summer when its over 100 degrees outside and to augment the swamp cooler, I sometimes block off one of the returns on the upper level and use the fan-only setting to help pull some of the cool air from the lower level and distribute it to the upper level. The downstairs temp can be 10-20 degrees cooler than upstairs, so that mixing of the air does help. Maybe that jumper will give me greater airflow out of the registers, resulting in an even better distribution of the cool air. If it's too noisy and/or it appears to be taxing the motor, I'll bag it and stick with what I have and what currently does work. Thanks again for the valued replies.