Tracking significant voltage drop

Hi guys,

I’ve been trying to track down the source of resistance/failed component in my 650 for a little while now. It was working alright before I put it away for the winter but after installing my new Dyna S I realized I was only getting 2.5v to the coils. This voltage drop can be measured anywhere in the system that’s supposed to have 12v (starter relay etc). When the key is in park the voltage goes up slightly but is still only about half of battery voltage. I rebuilt the kill switch, replaced the ignition switch (old and new act the same), replaced the fuse box assembly, cleaned the hi/lot switch for the headlight and many of the connections under the tank. Does this sound like a harness issue or a component failure? Would just replacing the entire harness fix my problem?

It should also be noted that when the key is on all of the lights are very dim/basically off.

Is the battery any good? When was it last charged and have you ever had it load tested?

I replaced it last season but accidentally left it in my bike over the winter, bought a tender a month ago and charged it up but the charger never switched from trickle to done. Got up to 13.5v but went down to
~9v pretty quick. Never had it load checked

Lead batterys can easy lost power capacity ( voltage drop) that way by sulfite build up between the lead/zinc cells.

It could well be the battery is not up to suff, so to speak. But you might want to check out this link for info on doing voltage drop tests.

www.motorcycleproject.com/text/volt_drop_test.html