E32 Lic Plate Lights Error

1994 740iL The Lic Plate Lights (in trunk lid) will not turn on. Interesting thing is that when I lift the trunk lid to the full stop, they both turn on. When I
lower the trunk lid, they turn off again. Any ideas from you electrical gurus? I need to get these working to pass VA inspection.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'd be looking at the wire harness where it goes into the trunk lid. My guess is that the wires going to the license plate light are broken due to the flex that comes from opening and closing the trunk.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks Jeff and Petrus - I would agree except that the trunk lights go on at exactly the same time that the lic plate lights go off. Since I just bought the car, I dont know how the lights are supposed to work. But this is how it works now: When you pop the trunk the lic plate lights turn on. As the trunk lid hits the top stop, the lic plates turn off (which also illuminate the trunk area) and the trunk lights turn on. These lights behave the same way whether the headlights are on or off. The only problem is that the lic plates never turn on when the headlights turn on. So, it may be that the current on/off behavior is normal (but I dont know since I just bought the car) but the switch over between lic plate lights and trunk lights is exactly the same time - like they were being controlled by a switch. Is there a lic plate light sending unit somewhere that I should check? Anyone have an E32 or E34 that can verify that this behavior is normal?

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You have a problem with a ground somewhere.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

1. Bad connection... when you lift the trunk, it moves the wires around and makes a good connection. Wiggle things and see.
2. Bad ground... but when the trunk light is turned on, the license plate lights get grounded through the trunk light circuit.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'll check it out and get back - thx

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
thx - I found the problem just as you described - broken ground wire in the articulating portion of the harness

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.