I have had an intermittent issue with the back up lamps/sonar since I got the car four years ago and now finally trying to get to the bottom of it...

2004 X350, 148,000 miles

Symptoms...
Backup lamps/sonar come on when they feel like it. Seldom right away, sometimes half way down the driveway, most times not at all.

Finally opened up the trunk and jiggled around. As soon as I touched F46 10amp (right hand reverse bulb) fuse they came on. Fuse looks good - put in a brand new fuse anyway.

Did some looking on line and found the rear electronic module. Checked all connections, nothing loose and lights did not work during that period.

Play around with F46 and on they come....

shut off ignition and let things cool down.
Try again and after 10 minutes, same thing. touch the fuse box at F46 and they come on. Turn off car and try right away again. they all work....

Let the car sit for ten minutes, put in reverse and lights come on after the count of three.

It's like a contact needs to warm up to make the connection.

My question is this. Is there a relay involved?
Doesn't seem to have anything to do with the rear electronic module.


I am suspecting the rear fuse box.

Any other sage advice???

Regards,
Tom

 

This morning, 38 degrees, put selector into reverse and it takes 8 seconds for the light/sonar to come on. Leave it it place for a few seconds.... Back into park and then reverse, three seconds to connect.... Back into park and then reverse, lights right away from then on...

Mirror dips as it should with the selector in reverse each time, back up lights do not. Where is that connection made?

Get to work and mirror dips with the selector but lights/sonar never come on. Hmmmm.

Regards,
Tom
2004 XJ8

 

I would check for an intermittent connection in the fuse box at that fuse location.