Grab the alternator pulley and give it a vicious twist left and right. It should lock up when twisted to the right and slip when twisted to the left. Any noises:
https://www.newparts.com/product/ina-al ... -150-00-60As far as the fan goes, I'm very happy with the E300 version of the fan system. I had an electric system that performed great. Then one day crawling up a ridge in the White Mountains, the heat got to the main relay and it melted down. Unfortunately, I was preoccupied with a very rocky trail and the engine boiled over violently.
Here is the E300 setup. It pulls enough air to very noticeably slow the engine down.
A6052000820 72mm water pump, just in case you don't already have that.
A6032050110 Smaller diameter water pump pulley
A6062000123 E300 11 blade fan (not the hub)
A6062000122 E300 fan hub (thermostatic) (multiple vendors, Sachs seems to be the best)