1993 Es300 Erratic Trunk Release Button

donbryce · May 24, 2010

I just bought this car about a month ago. About a week after getting it, I pushed the trunk release switch on the door and the switch fell inside the door, so I removed the door panel and secured it with a piece of aluminum bracket. It's now very secure. While it was out, I took the switch apart and cleaned up the contacts for the trunk release, tested it and it opened the trunk every time (while plugged into the harness, out of the door). The in glovebox switch seems to work OK, cutting power to the door switch when out and connecting when in. However, 99% of the time the trunk latch won't release with the door switch unless the key is turned to ACC or ON. If I turn the key to the first position, it releases every time. Otherwise, with the key out, it will only release once in awhile. Any ideas as to why the key in the ACC position would enable the trunk release to work?

donbryce · May 30, 2010

OK, problem solved (I think). I found 2 broken wires in the harness leading into the driver's door, which explained why the driver's outside power mirror didn't work, and why the master door lock button wouldn't lock, only unlock, the doors. While in there, I double checked and re-cleaned the trunk switch/button, and checked the wire for continuity to the harness plug. All good.

I then held the door button down and pushed the glove box button out (off) and in again (on). I noticed that as long as the glove box button was held in tight with finger pressure, the door button worked every time, but it would fail if the glove box button was just set to the 'on' position. So I removed the glove box switch, disassembled it and bent the 2 contact lugs slightly upward. The design of this switch relies on the slight spring pressure of the button assembly contact bar on both of these lugs, not a great way to go IMO.

If this had failed to fix the problem, I'd just put in a jumper to permenantly allow the door button to always trip the trunk lid. I know the intent is to push the switch off and lock the glovebox to prevent the valet from getting into the trunk. Myself, the last time I experienced valet parking was on a holiday in Miami 30 years ago.

Oh, one last note....I got a Compustar remote (1WAMR-1600) with the car, but it didn't work to pop the trunk. After hours of searching, I finally found the installation manual for the remote ECU (CM5200), which also had a nice wiring pin-out label right on it. I scrounged up a tiny pin connector out of an old VCR and connected it to the wire from the door switch, which now allows me to use the remote to pop the trunk. Woo-Hoo :cheers: