Also check the ground wire from the pump to the front timing case cover. There is a short ground wire that terminates to a ring terminal on the front of the engine block.
The power for the water pump comes right from the top of the battery junction block as stated above. Check all the battery junction block connections. Some are snap-in, some are 13mm nuts.
My thermostat connection (MAP Cooling) wires have been hitting the subframe during hard acceleration. I had to de-pin the connector and put moisture seal heat shrink around it to protect them from hitting the subframe. It looks like the orange power wire (0.5mm) from the Junction Box (fuse 78 or 37 depending on your build date) powers the electronics in the water pump AND the MAP cooling in the thermostat. If that wire shorted to the subframe, it will pop the fuse.
E92 335i/6MT Dinan Stage 3: intercooler, oil cooler, intake, flash, exhaust, LW dual-mass flywheel.
Vishnu PWM methanol custom trunk mount, Diffsonline 3-clutch Salisbury custom diff, Ohlins Road and Track coilovers, Vorshlag camber plates, much more...
E28 M5 w/ buncha stuff, R171 SLK350