07 FLSTC Trying to locate what I believe is a drainage problem. I used a volt meter from positive battery terminal to each wire going to the terminal.

Main battery cable shows 0.1
the wire for the signal stabilizer shows 12.5 then starts dropping

The part in the picture shows 12.0 and fluctuates.

Can anyone tell me if this is normal for either part and what this part is in the picture?

 

When you disconnect the negative to the battery and put your amp meter in line with the key off. An alarm bike, you will see about 16-25 milliampers (mA) for 30 second. Will make a seeable and hearable spark just hooking the cable on. Then in 30 seconds it tapers off for a total of about 2.5 mA no alarm to 5 mA alarm EFI bike. Carb bike is 1.5mA alarm one 4mA. Is that your battery backup alarm

 

What he said. You can read the blinking alarm/security system with a volt meter.

And, from the looks of your picture you need to clean your cable connectors and battery terminals..

 

Darn I did it all wrong, I was using a volt meter going inline on positive side. Thanks for the advice, I will clean the terminals.