Help on GPS!

[Reefman]

Installed a new Garmin 541 over the weekend. Connections are exactly the same as before, running the hot wire to console bank of switches/fuses. Problem is when I go to start the engine as the starter engages the power blinks on the GPS then turns off. I notice my VHF and fish finder will dim momentarily then come back up to full power.
Do I have a weak battery???? Should I wire direct to battery with in-line fuses and by-pass the console bank? Get a new, stronger battery? Wire to one of the trolling motor batteries?
Any suggestions will be appreciated!