I used the electric fan (AC fan) to cool the 2.5-16v for years when it was NA and also when it was turbocharged, currently I'm using the same electric fan to cool my turbo charged 3.0-12v (m103 983) and so far I haven't had any problem with overheating (last saturday temps. here were 43-44 degs C).

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

On my 93 190e 2.3 I pulled both the mechanical fan (electric clutch) and auxiliary fan and replaced them with one large used (JY) electric puller fan from a Volvo. The electric fan is substantially more efficient and powerful than the 2 stock fans put together. I can sit in 100f heat with AC on for an hour and the temp gauge never touches 100C. The AC blows at 40f no matter what the speed or outside temperature.

The only concern I have about the conversion in this thread is the temp sensor you used. Those are notoriously unreliable and inaccurate. Keep a close eye on your temperature gauge. Your best bet in the long run is to use an automotive temperature switch.