'09 700 Rhino won't start

Hi,

Got my new MSD back and it works flawlessly....(previous one was defective).
Problem I have now is last night I installed a trickle charger to keep the battery fully charged. Went to start it today and it wouldn't start....It's cold here but it always started before. Unplugged the MSD and tried it with only the module, same thing. My dash display also went out but is back on and headlights wouldn't work but are working again. when trying to start it, the engine check light starts to flash........any ideas what to look for?
The trickle charger is a Battery Tender Junior and only puts out 750mA. I put the permanent attachment on it. I use the same on my 4 wheeler. Rhino started great last night and I let it run for about 1/2 hour and then installed the charger. wouldn't start today and then having problems with the display and headlights.
I don't hear the fuel pump pressurizing when I turn the key on.....any ideas?
The lights and display were both off again but fiddled around with switches, relays, etc. and they both came back on.
Thanks,
Scott