So I was working on my central locking system, which hasn't been working in years. I pulled the left door panel and found an alarm system wire with a crimp fitting pulled out. I thought my troubles were over and I could just put the panel back on and be done.
But Nooooooooooooo.
Pulled out the replay pack and re-spliced the wire. Put everything back together, go to open everything works go to lock and the motor stays running.
I start the trouble shooting procedure testing both vacuum and pressure using both a vacuum pump and pressure pump. My vacuum pump is old about a 35 year old blue point but hold vacuum well. My pressure pump is now a rare antique, purchased about 42 years ago when I raced 2 stroke Go-Karts and the rubber was deteriorating and it was defiantly leaking at a somewhat predictable rate. So I was working with a pump that I really didn't trust so my confidence was not high.
So I check vacuum and pressure of all lines and of course since I had a pump that was un trustworthy I ended up pulling the other door panel and the right side kick panel looking for the elusive "T" fitting. Which I never found. But I was able to check out all the lines and all the components and everything checked out.
So I put everything back together and it all worked fine. I was about to put the door panels back on and suddenly one last check and the pump stays on. A few more tries and it starts working fine again. A few more tries and it start not working again. And of course when it fd up it was in the pressure mode so all subsequent testing would need to be performed with an un trustworthy tool to find what was apparently an intermittent problem.
So carrying on doing what appeared to be going nowhere trouble shooting, I noticed every time the pump would run continuously there was a clicking noise that I was able to find at the gas cap lock. putting my hand over the actuator I could feel the leak.
So look no further problem solved. Now I just need parts. These are not real expensive parts so I decider to purchase no only the gas door actuator but both door actuators as well.
I figured after doing all the vacuum pods in my AC system on 2 cars and with the gas cap actuator now shot, it would be best to replace both door actuators whale I have the doors apart.
The three actuators and necessary hardware for install is $116.00 delivered. The trunk actuator was another $60 so I decided not to do that one since it was almost twice the price of the others and that area was not opened up yet.
My pressure pump is now a rare antique, purchased about 42 years ago when I raced 2 stroke Go-Karts and the rubber was deteriorating and it was defiantly leaking at a somewhat predictable rate.
I also found out that when you use the superseded actuator you will need to do major surgery on the new actuator. At least for P/N A124 800 21 75. Note, there are two other optional part number actuators A124 800 15 75 and A124 800 18 75 . Possibly one of them has the pressure port on the opposite side and wont require you to remove the cap and switch sides. Or maybe if you can find a 90° elbow instead of the straight one recommended by the EPC it will fit in as is. oediscountparts also sent me P/N 202 805 03 44 fittings instead of 129 805 04 44 fittings. Maybe the 129 ones are 90° and have been superseded by the 202 straights.
In any case the removal and switching of the cap is not too difficult but must be done carefully. The real trick is getting the male tab on both sides of the actuators under the lip and into the female slot. Start with one side engaged and hinge it closed off the engaged side, working carefully to nurse the other tab into the slot. (nobby don't be a perv).
On the car I started with the fuel door actuator. A major improvement. The car appeared to work fine but within about 10 min the car would just lock itself. So after performing the above mentioned surgery I installed the new door lock actuators.
Now I'm about to go out and see if the system held its vacuum for the last hour or so.
After fixing my all-vacuum system I found this for $20 and installed it. It works. It is wireless and each motor has 8 pounds of pull/push, enough to actuate the driver's side door, which is the toughest. The passenger door, fuel filler door and the trunk are a breeze.
I'm interested in adding this to my 87 560sl. Can I add this to the vehicle regardless of my non functioning central locking system? or is it depended on all vacuum system to work?
This is a stand alone electrical system. It does not rely on anything you may currently have. I capped all existing vacuum lines and removed all actuators, using their original mounting holes and lines to support the new wiring. The toughest part was to run wires through the door rubber boot. I used the old nylon antenna chord as the wire feeder.
I located the box behind the glove compartment and below climate control solenoids. It is accessed by removing two screws and dropping the cardboard flap in the foot well. Have not gauged the range yet but I can tell it is way better than the OEM remote on my R350.
That is what I was hoping you would say - not visible. Looks like you did a nice job fabricating some adapter plates to mount the solenoids in the various locations to meet the actuator rods. I guess the throw distance of the solenoid actuators was compatible with the vacuum actuators they replaced.
Yes, the throw is just right. I don't know how but these things know when enough is enough. When I go to lock the door lock tab from the inside with the door closed, they all respond and vice versa. Same thing happens when I use the key, though now I no longer have to. If you noticed, I bought the kit with only one master (5 wire vs 2 wire) actuator. I went ahead and ordered another 5 wire actuator for the passenger door for $5. It is nice to have access to ample supply of aluminum. Those nut plates came from the ex United 747-400 two of which were bought by Paul Allen for his Stratolaunch.
I had these motorised actuators only to remove them a few years later. The sound they made reminded me of cheap GM and Asian vehicles.
Instead, I got a 5 sec lock interface (converts the 1sec signal from the alarm/central lock to a 5 sec pulse - intended for aftermarket alarms for Mercedes cars with vacuum pumps) to drive a VW cruise control vac pump. Pump taps into CL feed via check valve and it allows me to lock and unlock as many times I like whilst engine is not running and also it overcomes the issues of less than perfect vacuum system.
I got a spare W126 boot CL pump lined up for further improvement as these are silent and inconspicuous
My 1984 system does not have a pump. Only vacuum tank, which is good for a 3 - 4 cycles. I considered modifying my system to use a pump, but decided to give this $20 system a shot first. So far I am quite happy with it. Who knows, perhaps two years down the road I will revert back to using vacuum. The interface takes a 1/2 second pulse and converts it to a 5 second pulse to drive the pump long enough to actuate the locks, a good solution for those who already have a vacuum pump driven system to begin with.
I may be able to take a picture and reverse engineer it later this year when I address a few issues in the footwhel
Aftermarket alarms normally provide ~0.5sec pulse to drive CL motorised actuators. This is good for one that is needed to actuate the driver's door (where vac control valve is).
0.5 sec is not enough for vac pump to replenish used up vacuum
"the 5 sec interface" is triggered with normal 0.5sec pulse and provides a 5 sec pulse to drive the vacuum pump relay. vac pump is connected to tap into vacuum CL via check valve.
Each time remote is clicked, vac pump adds 5 sec of vacuum to replenish used up.
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