More starter problems?
What’s more useless than a plane stuck in the snow? A plane that won’t start. Like last winter we’re having problems again. We (the owners) have replaced the starter, the battery, and the voltage regulator based on expert mechanic’s advice and debugging. But it’s still having problems turning over in colder weather when left idle.
The clock draws power even when the master switch is off - but I figured that to be about a 1/2 Watt-hour per week. Not enough to be a sole cause to this problem. Granted it’s in the mid 30s when I tried to start it (about 2 degC). The battery’s useable charge is about half its rated charge level at this temperature, this pushes something else marginal just too far and the engine won’t turn over. If the engine turns over, it’ll catch reliably though. So not an engine problem.
Ok, that leaves the charging system. Which we’ve replaced a lot of already. That leaves connections and cables. The greybeards on a local pilot’s email list are recommending (from their experience) to check the grounding connections especially. Of course current needs a full circuit path from the battery, to the starter motor, back to the battery. If the ground connection is bad, that return path doesn’t work well. The starter motor draws around 200 amps. This means that any small resistance creates a large voltage drop. (Ohm’s law: V = IR)
So when I can (weather and work permitting) I’ll charge up the battery, check cables during cranking, and verify grounding connections. I’ll also validate the components in the system too.