Date: Sun, 08 Sep 2002 00:56:31 GMT From: "Charles Stoyer" <cstoyernopsamrpex.com> Subject: More on 86 900 Central Locking Broken -FIXED!
Well, it's fixed for now. Thanks for your advice, but the CLCU is really behind the kick panel under the glove box (LHD USA Model), screwed to a clamp which sits on top of the heater distribution plastic thing. My fuses weren't blown, so I figured the lock motors were OK. And yes, I want to share what I found. I took it apart and the unit is in a black plastic box which does come apart. There are two flat barbs which can be disabled with a thin screwdriver while prying the unit apart with a bigger screwdriver and there is a circuit board with resistors, capacitors, transistors, diodes and relays. I found two suspicous solder joints and reheated them. Reheated a couple more as well. Then tested. Still no locking but the two relays did seem to work. Probably worked before I started. There are 8 possible connections but only six are used. One 12V one Ground. Two for the switch on driver's side door. Two for the locking motors. When the driver's side door switch changes, one relay or the other switches on for about 1 second. Normally both relays connect the locking motors to ground, both sides. When a relay change state for one second, the locking motors are powered to lock or unlock, depending on which relay. No voltage at the relay in the trunk (this is a 3-D Hatchback). A closer look at the circuit board in the CLCU showed a resistor looking thing about in the center vertically and 23 towards the pin connector laterally, which used to have a thin brass strip soldered to it. It reminded me of the low temp solder connection on the old V4 clocks, these were designed to protect the clock, but would sometimes fail with age and resoldering them would fix the clock. So I resoldered it, using the original solder (pretty much) and it works again. We'll see how many lock/unlock cycles it will last. I am going to try to find a reasonable used unit in case it happens again because it's a bit of trouble getting the darn thing in and out. So there you have it, Charles.