Hi Folks, I had my recent fit and headaches with the alarm/security/door lock system on a 96 P38. Which also involved a myriad of misleading issues the least of which was having a disabled vehicle with no one willing to take it for a drive including me. After all half the fear is how much is going to cost in time and money if, 'Ermintrude' which is what I call my p38 decided to throw a fit and disable the engine or lock you out in goodness knows where.
So back to basics, the drivers door latches and locks.
Step one, I took out the drivers door latch and dismembered it to observe this gremlin every one who posts regarding this issue of EKA and locking accuses. It would however seem that in most cases it is the micro switches within that assembly that appear to go bad.
Step two. Tested the switches using a simple open and short continuity tester (For those of you who just want to test insitu without going as far as I did too affirm malfunction. Simply gain access to the door latch connectors. There are two on this vehicle, one 6 pin and one single black. Detach them and simply hook up the negative lead on your probe/meter/buzzer to the black wire and the positive lead of your tester to white, blue, red each in turn and operate the key to confirm a result. All mine read open circuit.
I found not only is this a common problem that plagues the fancy RR security system but one that many electronics technicians will come across. Yes simply dry solder joints, indeed the three set micro switch is prone to this problem too or perhaps our expensive microswitch was switched for inferior manufacturing during a cost saving drive who knows. The micro switch is a Cherry NM-13-0012, and apparently as hard to find as unicorn poop.
I discovered this problem by pulling on the wires to find that I got a closed circuit indication which aroused my suspicions, So in pursuit of a cheap solution after finding out the price of a latch I would not deny myself the adventure of examining closely the microswitch assembly itself.
I removed the pcb assembly filler using a small blowtorch gently applied to surrounding seal where the wires connect and are duly buried. I then simply gently dug out the softish epoxy material which took about 45 mins with a crafting scalpel. On revealing the small PCB which the microswitches are mounted on ( hidden side) I specifically targeted and cleaned carefully all the solder joints in order that I could re solder them.
I used a low wattage soldering iron gently reapplying solder to all visible joints even if there were no wires connected. Well voila on retesting all the connections worked and I had a positive signal on depressing the switches. I then gave the switch a final test before applying epoxy to replace the factory resin or whatever it is. Reassembled the lock and micro switch with refit back into the vehicle. Operating by key is now not hit and miss but works every time,and with this gremlin resolved I can now clean out and service the vehicle with a little confidence that she can be driven and also faithful.
Thanks to the forum poster/s Auslander, I believe who suggested the 7 pin connector jumper to the door module which got me out out of trouble and home.
So back to basics, the drivers door latches and locks.
Step one, I took out the drivers door latch and dismembered it to observe this gremlin every one who posts regarding this issue of EKA and locking accuses. It would however seem that in most cases it is the micro switches within that assembly that appear to go bad.
Step two. Tested the switches using a simple open and short continuity tester (For those of you who just want to test insitu without going as far as I did too affirm malfunction. Simply gain access to the door latch connectors. There are two on this vehicle, one 6 pin and one single black. Detach them and simply hook up the negative lead on your probe/meter/buzzer to the black wire and the positive lead of your tester to white, blue, red each in turn and operate the key to confirm a result. All mine read open circuit.
I found not only is this a common problem that plagues the fancy RR security system but one that many electronics technicians will come across. Yes simply dry solder joints, indeed the three set micro switch is prone to this problem too or perhaps our expensive microswitch was switched for inferior manufacturing during a cost saving drive who knows. The micro switch is a Cherry NM-13-0012, and apparently as hard to find as unicorn poop.
I discovered this problem by pulling on the wires to find that I got a closed circuit indication which aroused my suspicions, So in pursuit of a cheap solution after finding out the price of a latch I would not deny myself the adventure of examining closely the microswitch assembly itself.
I removed the pcb assembly filler using a small blowtorch gently applied to surrounding seal where the wires connect and are duly buried. I then simply gently dug out the softish epoxy material which took about 45 mins with a crafting scalpel. On revealing the small PCB which the microswitches are mounted on ( hidden side) I specifically targeted and cleaned carefully all the solder joints in order that I could re solder them.
I used a low wattage soldering iron gently reapplying solder to all visible joints even if there were no wires connected. Well voila on retesting all the connections worked and I had a positive signal on depressing the switches. I then gave the switch a final test before applying epoxy to replace the factory resin or whatever it is. Reassembled the lock and micro switch with refit back into the vehicle. Operating by key is now not hit and miss but works every time,and with this gremlin resolved I can now clean out and service the vehicle with a little confidence that she can be driven and also faithful.
Thanks to the forum poster/s Auslander, I believe who suggested the 7 pin connector jumper to the door module which got me out out of trouble and home.