Sorry, couldn't help myself. I have a True isolator, probably the most popular option from what I've read. Easy to install, well thought out, effective.
None that I know of. But all of them if wired incorrectly.
One guy has his wired to a ground.
I have sold a few 1000 of the TrueAM Isolators.
While there have been a few bad ones, like any product, nothing major.
Most of the bad ones had water damage from a cracked case.
Usually around the 2 screw mount holes and appeared to be over tightened and cracked.
It was to the starter side of the starter solenoid.
It is only hot during cranking, Otherwise it test as a false ground.
He ment to put it on the battery side.
I seen it in his pictures and told him. lol.