Fan Clutch water pump questions
 

I am getting ready to replace the water pump in my 2002 Blazer. It just started leaking from the weep hole. Many people have suggested replacing the fan clutch while it’s off. Here is my question:
My 2002 Blazer when it’s hot 85 deg and up and AC is on. I am driving in town or somewhat stop and go traffic. When I start off from a light or a stop, the fan roars and power drops off dramatically for a bit. This also occurs when pulling a trailer. My 1998 rarely has this issue.
When the 2002 was new we returned it to the dealer for a check on the fan but was told it was “functioning correctly”
Neither vehicle overheats, I'm just curious which one is correct?
If you chime in please indicate what year you have… Thanks

I have never replaced a fan clutch, ever.
'00 Blazer 183,000 miles 4.3L V6
'93 S10-Blazer 206,000 miles 4.3L V6
'87 S10-Blazer 190,000 miles 2.8L V6
'97 Astro Van 286,000 miles 4.3L V6

Never replaced a fan clutch on any of my other vehicles either.

My roaring engine turned out to be a mal-functioning TPS. IT only acted up with teh a/c on, or when the engine temps were close to 200.

How did you come to find it was your TPS? Throttle Position Sensor?