How can you unstick an air conditioner/ heating unit fan relay if it is stuck? Where is it located? I have tried turnng the thermostat and power off, but to no avail.:o

The blower control relay on most residential split systems is located on the circuit board itself unless it is an older system that uses a combination fan/high limit switch. If it is on the circuit board then you may as well plan on changing out the board itself. If it stuck once then it will stick again.

Yeah, a whop with a screw driver handle often does it, but it is a short lived fix.

For pictures of many furnace and A/C components browse https://www.askmehelpdesk.com/heating-air-conditioning/heating-cooling-maintenance-repair-troubleshooting-frequently-asked-questions-58313.html

If you note the positions of the wires before removing a board, a new on is much easier to install than pay for.