I would say replace the pump, if it is some ware between 4 to 5 years old, its probably not putting out like when it was new, I wouldn't think a Mag drive would last too much longer anyway....LOL

Oh by the way , you said you checked the pump, does that mean you took it apart and cleaned it and inspected it for ware ?

IMO, I can't see how the pump has anything to do with the fuse as it is wired seperately from the chiller. Maybe if the chiller is overworked due to lack of flow, but I would think the chiller would have to be running constantly to blow fuses. Is it running way more than usual? I think you have an electrical problem within your chiller.

If the chiller is running harder due to less flow ( IE: a worn out pump) it will cycle on longer , over heat and self protect by blowing fuses.
As Christyf5 said putting a fan in front of it has helped ( a temporary fix) The fan is helping the chiller to run cooler....or preventing the over heating situation...

Basically what I was getting at is that if the unit isn't running more that it normally does, it's likely a problem within the chiller. Christy didn't describe that it was running more than usuall, that's why I have the opinion that it's likely a problem with the chiller.

my chiller blows fuses the second it turns on, still havent had a chance to get it fixed, but would having a lower flow pump on the chiller and having the chiller in a smaller tank make it work alot less?

With the PCI chiller, it needs a minimum amount of flow or the fuses will blow. Temp draw down doesn't seem to make a difference, as long as good water flow and good external venting is present. If the fuse is blowing the split second it turns on, it sounds like an electrical issue (shorting out)

It's quite likely the compressor is failing and cannot start properly without drawing excess current, thus the fuse blowing. What you can try is making sure the fuses are of the "slow blow" type vs the "fast blow" type. They can take additional inrush current for a split second without immediately blowing.