Will not start after replacing the fan clutch

Hello,

One of the signs of a blown head gasket is white smoke out of the tailpipe.
Check your oil, does it have the milky while residue?

Here is a helpful guide that goes over the signs of a blown head gasket:

https://www.2carpros.com/articles/white-smoke-or-steam-coming-from-the-exhaust-pipe

What symptoms did you have before this issue?

When try to start it what happens? Does it crank but not start?

Let me know little more details of what you have been experiencing.

Thank you.

Generally speaking, an engine will need spark, fuel and compression to start. Let me know what you find out on the compression test.
The standard compression for this engine is 192 PSI. The minimum is 142 PSI. The maximum difference between the highest and lowest cylinder should not be more than 14 PSI.

So, you will need to check for spark, fuel and compression. As you know missing either of these will prevent the engine from starting.

Have you checked to see if there are strong blue sparks to the plugs?

https://www.2carpros.com/articles/how-to-test-an-ignition-system

When you turn the key, can you hear the fuel pump kick on?

You might want to do a chemical test for blown head gasket. It is possible to have small amount of coolant that is not really changing the coolant color but causing the white smoke.

https://www.2carpros.com/articles/head-gasket-blown-test

And besides the head gasket, white smoke can be due to cracked cylinder head, bad block, intake manifold gasket leak or crack in the manifold.
Good process would be to eliminate each possibility.