The dishes are pretty wet as is the inside of the dishwasher after a regular run. will a rinse agent fix this?

Hello,
One common issue on these units is the heater wire will fall off. If this happens, the dishwasher will not heat. Also make sure the rinse agent is full. On most of the newer dishwasher rinse agent must be used to help dry the dishes.
Appliance & Refrigerator Repair

You have to buy a cartridge type water softener and attach it to the
inlet water line of your dish washer. In addition to this there must be
a salt compartment in the dish washer.
Refer the user guide /owners manual and locate. Fill it with the special
dish washer salt. ( Do not use kitchen salt used for food).
The dish washer salt may help to certain extent in softening the wash
tub water inside. Check the switch settings for rinse aid and salt
release settings in the machine. Refer manual!

Visit Bosch web site and get a user manual. Or tray the authorized service center

if no rinse agent is present it doesnt matter how hot the water gets they will still not dry check unit make sure it is full. rinse agent is only to aid the drying process the machine will wash happily without it but not dry.

NO WILL STILL WORK IS ONLY A FLOAT SWITCH TO WARN YOU,HOWEVER RINSE AGENT DOES AID THE DRYING PROCESS SO WITHOUT YOURE DISHES WILL BE WET AND SMEARY

Look inside and see if all the water is gone at the end of a cycle - none standing in the bottom of the washer in the sump.

Most dishwasher detergents now have some sort of rinse agent already in them. If this is the case don't add it to your dispenser once it runs out. Too much rinse agent can cause clouding.

I found that if the rinse agent (Jet Blue) has run out the dishes stay wet.

If it's a Bosch, check for Rinse Agent (e.g. JetDry). Rinse agent is not optional with a Bosch.

Make sure that the drain hose is connected as per manufacturer instructions, and that there isn't a direct run down from the sink u-bend to the machine. The rinse agent effects dishes dry but has nothing with the water remaining in the machine. Good luck!