Hi all: I have a 1996 4runner SR5, RWD, 3.4 ltr. After driving it for a while and after it is turned off I hear an intermittent buzzing noise coming from near the engine. It buzzes twice in about a second, then after a couple of seconds it does it again. This goes on for quite some time. It sounds like an "electrical" sound. The actual sound comes from about "one step" in front of the driver side (left side), towards the top of the engine bay, from a black box. Any ideas on what could it be? is it serious?
This has been going on for quite some time now. It does not happen all the time, but it keeps getting louder a little bit at a time. At first I though it was a dragonfly or something like that caught in the engine compartment, we have all sorts of critters here in FL. Anything that will point me in the right direction will be greatly appreciated.
Thank you in advance,
FC