There are two fans on the V6 24v. In fact I have an override switch for these in case of temperature sensor fault - 30+ degrees here Monday! A highly recommended and cheap mod but you must remember to switch it off as it, like the fans which cut in via the sensor, is not via the igntion!

Can you post a photo of the relay case you are talking about? There are relay housings either side of the rad!

 

They are the same a single fan motor and blad. There is only 2 (dual) fans on the Q4 CF2. Either or will work, dual will need more wiring.
I really suggest making sure the 2 speeds are working correctly and nothing has been bypassed (resistor). Check for low speed with A/C on and then check to make sure high speed is working.
I have never needed any special switch, bypass or anything else to keep cool in Phoenix Arizona. As you may know we see 43˚C-46˚C here. I run hot but nothing that I worry about since my gauge along with most 164 gauges are off by at least 10˚, mine is 35˚F off.

Relays under black cover (black relays). Others are fuel pump/motronic (red strip)
50/50 mix and proper bleeding of the system as well.

Jason

 

Jason,

Just went and had a look at my 164 24v Super auto and that has two (smaller) fans !

 

2,5 TB/DS (CEE-F2) Supers came with duals with A/C BUT not all, w/o A/C came with single fan. But no V6 supers.
V6 Super only came with a single fan.
No 164 except for the Q4, 2,5 TB/DS (CEE-F2) A/C version came with a Dual fan (155 shared the same fan as the later Q4).
You may be confusing the automatic transmission smaller fan.

I guarantee it did not come with a dual fan if a V6 (which I am assuming it may be?), unless previous owner installed a Q4 an.
Dual fan set up on Q4 is two equal size fans that cross the radiator only.

This is the dual fan for the Q4, f you have this on your Super it is an after thought as they did not come with dual fans or you have a 2,5 TB/DS (CEE-F2) which was not detailed in this post.
*Early Q4's as well only came with single fan (which I assume you have as well) only Fl Q4 came with dual:
http://image1.frappr.com/pix1/i/20080630/4/f/e/4fec5b8d63b3597e472ab7f433e417d00_large.jpg

 

My Super and QV only have one fan. And they both look the same size as the TS, though I couldn't guarantee it…