Trunk lid open warning and electrical latch release problem

Jake of Sigourney · Post by **Jake of Sigourney** » 22 Sep 2009, 17:16

2001 S80, 106K miles

Fixed problems with my son's Volvo: trunk lid open warning stayed on, trunk light stayed on, and key fob would not open trunk latch.

Removed latch assembly and measured micro switch function on leads coming from assembly. This normally open switch functioned OK. Then measured continuity from each side of switch out to gray connector inside fender near left tail light assembly. One side was open. Tugged, and twisted, and compressed lengthwise the black cable bundle that goes from car to trunk lid. At its point of maximal bend (when trunk lid closed) an intermittent continuity break was found.

Dissected the bundle and found two "bent" wires. Placing soldering gun to "bend" and lightly tugging, both wires readily parted at the fracture site. Soldered in patch link, taped and closed the bundle covering back around wires. One fractured wire was to "latch closed" micro switch and the other to the release solenoid. Problem resolved.

This was (hopefully now improved) a design and quality control issue with 2001 Volvo S80. The point of maximal bend (stress) of the cable bundle is at the apex of the loop when lid closed, and it over stresses the copper stranded wire, failed here within 7 years of regular use. They could have secured the cable bundle in a stiff plastic sheath or included a metal spring wire or plastic rod and thus kept the radius of curvature maximized when the lid was closed.

Mr Craig · Post by **Mr Craig** » 08 Oct 2009, 09:29

Hey Thanks, I have the same problem. I'll check it out!!!!!!

Jake of Sigourney · Post by **Jake of Sigourney** » 08 Oct 2009, 23:01

Mr Craig wrote:Hey Thanks, I have the same problem. I'll check it out!!!!!!

Mr. Craig,
To isolate the problem, you might simply close the trunk latch while the lid is open, using a screwdriver, etc. The trunk light should then go out. If not, then a wire is not conducting the closed micro-switch signal (this normal open switch is located within the latch housing, and closes with latch locking). Try bending the black wire bundle where it makes a loop just before passing through the grommet seal into the trunk cavity. If you can isolate the approximate location of the intermittent conduction, then use a single edge razor or sharp knife to carefully slice open the black outer sheath, exposing the individual wires. You can then push and bend them individually, and locate the culprit(s), Solder in a new link, tape the junctions, and close the sheath by taping. It should work many years. Finally, remember to push the trunk open button, to reset the latch. Best of Luck // Jake