Where is the thermostat located on a 1.6 1996 polo classic

Question edited for clarity.

All the relays are in a block under the dash.

Volkswagen Polo (9N; 2002-2009) fuses and relays

Fuse Box Diagrams https://fuse-box.info > volkswagen > volkswagen-polo-...
Fuse Box Location. The fuse panel is located behind an access panel on driver's side edge of the instrument panel. Location of the fuses in the passenger ...

https://www.google.com/search?q=2007+volkswagen+polo+classic+headlight+relay

..

Question edited for clarity.
Question moved to model category.

Need year as well ideally

https://www.google.com/search?q=vw+polo+playa+fuel+pump+relay+location

Volkswagen Polo 3 Classic fuse and relay

FuseAndRelay.com https://fuseandrelay.com > volkswagen > polo-3-classic

It is located under the dashboard on the driver's side and is covered by a protective cover. Block location. Type 1.

Volkswagen Polo (mk6; 2018-2022) fuses and relays

Fuse Box Diagrams https://fuse-box.info > volkswagen > volkswagen-polo...

Here you will find fuse box diagrams of Volkswagen Polo 2018, 2029, 2020, 2021, and 2022 get information about the location of the fuse panels inside the car, ...

Volkswagen Polo (9N; 2002-2009) fuses and relays

Fuse Box Diagrams https://fuse-box.info > volkswagen > volkswagen-polo...

Here you will find fuse box diagrams of Volkswagen Polo 2002, 2003, 2004, 2005, 2006, 2007, 2008, and 2009, get information about the location of the fuse ...

https://www.google.com/search?q=Engine+diagram+92+geo+storm+gsi&biw=1362&bih=650&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjYzZrkhpjQAhWBfCYKHd5eCVMQsAQIGg#tbm=isch&q=How+do+i+replace+a+relay+on+my+polo+classic+1%2C6+2002+model%3F+where+is+it+located%3F
Hope this helps

Hi. On the fuel tank under the rear of the car.

follow the top radiator hose back to the engine,the thermostat is in that housing unbolt the 2 bolts and take it out

Visit the on-line store, known as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
Best Manuals

Check fan relay or temp sensor.

Yes but that wouldn't help if you still have an over heating problem. To correct the problem, you need to replace your VW OEM plastic impeller water pump to an aftermarket metal impeller water pump. Plastic cracks at the shaft which the pulley drives and spins slower than engine speed or not at all. It's also a good time to do a timing belt service when you do this because it has to be removed out of the way to get to the pump.

this sounds like a thermostat fault, but also could be the sensor switch to the radiator but is more likely the thermostat, it should be located at the front top of engine, follow the top water hose to the engine and you will find the thermostat housing, also just a heads up, these had a problem when first made, according to the known fixes and problems with VW's the hoses corroded inside and started loosing water, this could be wise to get the system presure checked to...hope this helps

Try moving the fan blades by hand to see if the fan spins freely to see if the problem is frozen bearings in the fan motor. Replace the fan motor if it doesn't turn. If it spins freely disconnect the wires and hook the fan directly to the battery using a jumper. If it runs the problem is most likely the thermostatic switch. If it doesn't the fan motor is bad.