2005 Vue 2.2 Manual. Help with Backup Lamp Circuit

[Beasleylou]

I have no power at the backup lamps.
I have power at the fuse.
Key on I have power power at the backup switch connector pink wire.
Key on shifter in reverse I have power on the light-green wire at the backup switch connector so switch is ok.
Key on shifter in reverse I have no power at the light-green wire in the rearview mirror so presumably the problem is in the front somewhere?

Before I start unraveling wiring I was hoping someone had some idea where a likely light-green wire break would be in the engine compartment. Is there a connector somewhere?

Thanks.

[far2grumpy]

Originally Posted by Beasleylou

I have no power at the backup lamps.
I have power at the fuse.
Key on I have power power at the backup switch connector pink wire.
Key on shifter in reverse I have power on the light-green wire at the backup switch connector so switch is ok.
Key on shifter in reverse I have no power at the light-green wire in the rearview mirror so presumably the problem is in the front somewhere?

Before I start unraveling wiring I was hoping someone had some idea where a likely light-green wire break would be in the engine compartment. Is there a connector somewhere?

Thanks.

See thumbnails - L-GN wire routed from BACKUP SWITCH to Underhood Fuse Block (UHFB) - enters connector C2 - contact A12.

The BU voltage is split inside UHFB and normally goes to mirror (C3-A1) and two L-GN wires will be connected to C3-A5 going the rear lamps.

Wires entering bottom of UHFB have been known to break due to sharp bends so you might try wigging harnesses to confirm open circuit is outside UHFB.

[Beasleylou]

I pierced the light-green wire found in a small bundle maybe 5-6 inches from the back of the box and found batt voltage ok.

As you say break is likely where the wires come together and enter the box. Tried wiggling... no joy.

Thanks for the box diagram. Too cold now to attempt taking that box apart. May have to wait until spring.

[far2grumpy]

Originally Posted by Beasleylou

I pierced the light-green wire found in a small bundle maybe 5-6 inches from the back of the box and found batt voltage ok.

As you say break is likely where the wires come together and enter the box. Tried wiggling... no joy.

Thanks for the box diagram. Too cold now to attempt taking that box apart. May have to wait until spring.

According to BU diagrams voltage supply and three wires routed to mirror and tail fixtures are all part of CKT 24 and all light green.

Is it possible the small harness you located has other light green wires?

If yes I'd be tempted to "test-connect" supply wire to another light green wire ... if successful ... tie all together and bypass the UHFB.

[Beasleylou]

I’m sure I had the right conduit. I followed it up from the backup switch connector and the other (speed sensor?) connector on top of the transmission.
Its a maybe 10mm plastic tube with only 5-6 wires.

[bern]

You can also Run a jumper wire To the mirror circuit 24, if the reverse lights come on everything in back is good