A weak 12 volt battery won't cause flicker, especially on the Insight, because 12-volt power is coming from the DC-DC converter. Easy to check this if you have a ScanGauge or similar. Set it to show voltage: when the DC-DC is active, it'll show about 14.4 volts, if it's just drawing from the battery (which it does sometimes) it'll be in the 12.X volt range.
You can get a situation where the DC-DC doesn't come on properly, and voltage will drop into the 11.X range. If this happens, you'll see headlights dim, and get (IIRC) the battery and brake warning lights lit up. Usually turning the switch off for a couple of seconds (while coasting) then back on would kick the DC-DC back on, but long-term fix was to re-balance the battery pack.
|