3 clicks from the back when starting

sorry not understanding your issue.The clicks in the back are the main power relays they connect the hybrid battery to the car.

Be more definitive in what you need please.

 

There are three relays back there, SMRB, SMRG, and SMRP.

When you ready the car, SMRP and SMRG pull in simultaneously; you hear that as one click.

After a fraction of a second to precharge the inverter capacitors through SMRP, SMRB pulls in. That's the second click you hear. Just after that, SMRP is released, the third click.

Normal in every Prius ever.

 

welcome!
test your 12v battery health

 

WHAT ??

I think you are focusing on the wrong thing(s) here.
The car refused to start at least once.
Warning lights come on the dash.
The MFD display does not come on at least at time.

And yet you are worried about 3 clicks when starting ????

HIGHLY likely that if you fix the real problem(s) the clicking will go away.

 

First things first....

You previously popped the AM2 fuse, so most likely your inverter cooling water pump has failed or is failing. When the AM2 fuse opens, it also kills the dash, the MFD and really, the car. Bad stuff if you were driving on a busy road at the time. If you replaced the AM2, but didn't replace the inverter cooling water pump, most likely you have little to no cooling flow through the inverter, TA--Da......which would cause temperature issues for the inverter on anything more than short trips or slow trips. I would imagine those two items are related to each other....check the ICWP and have it replaced if needed.

If you start the car, but the dash does not light up (but the MFD is ok) then your combo meter is probably failing. It's pretty common. The car will drive normally, but you'll have no indication of speed, etc. You'll have to press the power button for about 10 seconds to get the car to turn off. Many times, it will work properly the very next time you start the car.