***EDIT, RESOLVED*** 240Z Buzzing box(relay?) near fuse box and no power!

[kaiserserser]

Hi Guys, 

 

I had pulled my engine to do some work on it and when I put it back in and attached the battery leads, I started getting this buzzing noise coming from the console area and nothing else seemed to be getting any power. 

 

I figured out the buzzing noise was coming from a little brass  box in the console area to the left of the fuse panel. From what I can tell it seems like a relay of some sort with three prongs and a fitted plug with 3 wires connected to it, but no part numbers on it. 

 

A few specifics:

 

The buzzing is 100% is coming from inside that little box that seems to be a relay. 

If I unplug that box/relay, the sound immediately stops, but I still have no power to lights/ignition etc

If left plugged in, the buzzing noise persists regardless of key position. .

Three wires plug into this box/relay but I can't tell where they come from. 

 

If anyone knows what might be causing this weird scenario I would really appreciate your  help!

 

 

Thanks, 

 

Jon

Edited September 10, 2018 by kaiserserser

[SteveJ]

Year? Photo of the offending part? Wire colors?

[kaiserserser]

Here are a few pics, it was attached just behind and to the left of the fuse box. One of the pics shows what it looks like inside the brass casing (After taking the pic I closed it back up and plugged in and still makes the buzz). Two black wires and a green wire going in. 

 

 

 

 

[SteveJ]

Green is usually associated with the wire coming off the ignition fuse. It provides power for the turn signals among other things. 

I scanned various FSMs, but I did not see this connector. Please supply the year of the car you're working on. There are wiring differences between the various years.

The device in question is a relay. I can tell that much.

[kaiserserser]

Thanks Steve! It's a 1973 240. 

 

It's odd if it's ignition related that it buzzes regardless of key position. 

[SteveJ]

From looking at the 73 wiring diagram, I would guess it has something to do with the seat belt buzzer, though the wiring diagram only shows 1 green & 1 black wire. Also, it should only buzz with the ignition in the ON position.

If I am correct, the buzzing and lack of power are unrelated. 

Unplug the buzzer and use a test light to see if you have 12 VDC to ground on any circuits in your fuse box.

[kaiserserser]

Hi Steve, 

 

I unplugged the relay/buzzer and still seem to be getting no power to anything. I'm curious with it being right by the fuse box if it's some sort of master relay or something (I'm a complete electrical novice)

 

However, if the buzzing and lack of power aren't related I'll be curious what the separate issues are, definitely weird that this random unmarked buzzing box with no part number seems to get power no matter the key position but nothing else gets any power ever. Really appreciate any help/advice you have to offer, definitely frustrating hunting down electrical gremlins!

[Mike]

Does it have a part number?

Looks like a flasher relay to me.  Here's where you can view the wiring diagram:

 

[kaiserserser]

Hey guys, thanks for all of the quick help and suggestions! 

 

I actually lucked into finding the issue. I saw online sometimes relays will rattle like that if they're getting a little power but not enough to lock in place. I started checking all of the connections from the battery toward the fuse box and found one spot that looks like it got a little frayed/pinched at some point, fixed that and the buzz went away and power came back to all systems!

 

Thanks again!

[Mike]

Nice work!  Thanks for letting us know...