02 Xt-SC: Relay clicking near fuse panel on Accessory

[XenonofArcticus]

So here's the thing. Nothing is broken or malfunctioning, but I'm getting the feeling something's amiss and I want to figure it out before it becomes a problem.

If I have the engine off, but the ignition to accessory (not on) so my son can listen to the radio, I sometimes hear a chattering of a relay from just above the interior fuse panel near the driver's left leg. Sometimes after chattering, things like the fan are powered, sometimes not. Seems like something wearing out. I didn't see any relays accessible in the fuse panel. Any insight?

[Big-Bird]

I was able to locate this image in my Factory Manual. Not sure why the fan turns on, unless the engine was warm when you tested for the noise.

[XenonofArcticus]

That looks like the culprit. By "fan" meant the interior cabin ventilation fan, not the engine fan. I'll look and see if I can see the relay and see how it is accessed. Anyone ever had this (relay clicking) happen? I'm wondering the the relay is bad, or if something else is causing the relay grief.

Unrelated: Anyone know what the whine is after the engine turns off? I notice it at night when I pull into the garage and close the door and shut off the ignition. It's not a fan that I can find. It almost sounds like it's coming from underneath, like fuel tank or something.

[Big-Bird]

There is a fuel pump in the tank that is most likely the culprit you seek.

Mine makes this noise when it sits for a few days as it equalizes the fuel pressure in the system just before starting. But I have heard it buzz occassionally when I shut my Xterra off.

[XenonofArcticus]

Yeah, that fits with what I have observed. I just wondered why it would be pumping something _after_ I turned off the engine. It continues, sometimes for a few minutes. Never seemed to harm anything. For all I know it's priming the flux capacitor for the next trip.

[Big-Bird]

The heater fan runs when the fan switch is turned on and the key in the accessory position. This is the way they were wired and it's one of my pet peeves about Nissan. My Hardbody Pickup did the same thing an I think my 1986 720 Nissan Pickup did it too.

[XenonofArcticus]

Hmm. I guess I never pictured that functionality as a problem. In what way does it bother you? Seems like it at least allows me to run the fan (if I wanted to), whereas disabiling it in accessory takes the choice away.

Granted, I can't recall the last time I needed the fan to run on accessory, but I'm not into having my truck think for me too much.