Has anyone else had problems with Garmin ZUMO shutting down when cranking up their Ultra Classic? I have 2007 FLHTCU WITH ZUMO 550. Checked voltage and it drops to 9 while cranking. It seems that the Garmin should switch to its internal battery on low or no voltage! My ZUMO is wired directly to battery. Voltage on stAnd alone battery is 12.67volts. I guess I can deal with it. My friends with metric bikes don't have the kind of voltage drop my v twin does.

 

there are many a things that can lead to the voltage drop you're describing, the main one being the battery itself. Has it been load tested? Have you tested the voltage drop at the battery itself? The voltage should not drop below 11v while cranking. Now if you're measuring the voltage drop at the power source for your zumo that could be anywhere in the electrical system of your bike including a ground. It's been a good while since I used the 550 but I don't recall ever having that issue. Usually when it switches from a supplied power source to battery, a message comes up on screen asking if you want to switch to battery power.

 

Check your battery and charging system. There are Stickys in the DIY Electrical section that give instructions. Your battery may be tired, not getting a decent charge, or your bike's circuits are losing power somewhere, such as poor grounds. Also check main battery power leads for being clean and tight at both ends.