98 jimmy I installed blend door actuator but the door is broke or jammed. As a temporary fix until I can get time to do it right so I could stop the heat and have ac I got two 5/8 pex ball valves off eBay for $21 and installed in the heater hoses near firewall that way just a quick turn of each I can go from heat to ac as needed. Like I said this is just a temporary fix so you can still bypass heater core but still use it

 

Simple but effective!!