Originally Posted by Twoxentrix
Odd, I have never heard a whine on either Espar units, I do occasionally here a clicking sound that comes from the fuel pump when it’s pulling fuel up from the tank.
Will file this in the back of my mind; At least now if I ever hear a whine I know where it’s likely coming from.
Yep some hate that clicking sound. My Hydronic water pump is what I suspect makes the noise. It also makes the same noise while shutting down and just figure it keeps coolant flowing as it cools. All I hear from the Airtronic is the fan blowing but with low voltage it will do the same; start for a minute, the fan ramps up and if it fails, then the fan makes a slight spin down noise.
To the OP, on my 2006 there is also a ground strip worth looking at. Mine is in the rear passenger wheel well area. But I'd still suspect you have a issue with a positive connection somewhere. There is also a high amp lug located close to the separator where my inverter connects to. I'd check that connection as well provided your build is similar. That's one of the problems...many builds are different. If you see any green on any connections, it can indicate a corrosion issue. Hope you find the issue.