Rear Cargo Door Lock Sensor?
- Thread starter Oxymoron
- Start date
autostaretx
Erratic Member
IT may not be very magnetic (i use flexible three-finger grabbers)
Life may be easier if you remove the interior tail light panel.
--dick
Hoppingmad
Member
I could be wrong.
Lock cycling,(and blinking red switch) press lock on remote and click click all locks unlocked, press again click click click and everybody locked (EXCEPT maybe the door with problem). In my case side cargo door..
I recall reading here once. Its mercedes way of telling you a fault exists
Or are you saying they just cycle without your input? Sounds like a short!
Lock cycling,(and blinking red switch) press lock on remote and click click all locks unlocked, press again click click click and everybody locked (EXCEPT maybe the door with problem). In my case side cargo door..
I recall reading here once. Its mercedes way of telling you a fault exists
Or are you saying they just cycle without your input? Sounds like a short!
The door may not be the original. On my Sprinter the side door was replaced and it is missing the door part of the power lock connection. So your right rear door may have been replaced with a door that had more options than you Sprinter had originally. Is there any indication of door replacement like paint mismatch, dents/bondo on the body around the door or the like?
As far as the lock cycling most electric door locks are simple solenoid affairs that use DC current to lock with one polarity and unlock when the when reverse polarity is applied. I doubt there is any sort of sensor to tell if the door is locked. My guess is all lock solenoids are clicking, not just the one in the rear door. If so the usual cause is something repeatedly sending a lock or unlock signal. This happens to me if something in my pocket gets jammed against one of the buttons on the remote.
If you need more help it would be beneficial to know several things:
1. Do all lock solenoids do the same thing at the same time?
2. Are the locks cycling (lock, unlock, lock...) or are the simply clicking at the last state (lock, lock, lock...) or (unlock, unlock, unlock...).
3. Was central locking original on your Sprinter or was it added later.
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autostaretx
Erratic Member
The Sprinter does have a sensor (switch) in the door lock mechanism itself... if the plunger doesn't fully "home", the "locking computer" (CTM) hears about it.
There have been forum members who have had the internal switch or other internal plastic bits fail, causing similar symptoms.
The Sprinter views a poor spring-pin connection as "door still open" and will do the lock/unlock dance if any door is in that state.
The red lights on the dash "lock doors" switch will flash if it thinks a door is ajar.
Here's the wiring inside the rear door mechanism. NOTE that it does require 4 spring pins:
(the upper contact plate powers the motor as wires said.. and the lower plate handles the sensing switches)
--dick
p.s. Oxymoron asked: "I'm sorry but what are the 3 finger grabbers? "
Something like this (ok: 4 fingers) ... almost any hardware store has them.
There have been forum members who have had the internal switch or other internal plastic bits fail, causing similar symptoms.
The Sprinter views a poor spring-pin connection as "door still open" and will do the lock/unlock dance if any door is in that state.
The red lights on the dash "lock doors" switch will flash if it thinks a door is ajar.
Here's the wiring inside the rear door mechanism. NOTE that it does require 4 spring pins:
(the upper contact plate powers the motor as wires said.. and the lower plate handles the sensing switches)
--dick
p.s. Oxymoron asked: "I'm sorry but what are the 3 finger grabbers? "
Something like this (ok: 4 fingers) ... almost any hardware store has them.
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Interesting. Most I have fooled with didn't have a lock status switch. I assume that would make the rear lock continue to click until it locked or current draw triggered a fault.
From the wiring diagram legend it appears that 4 pins are only on passenger models. The additional 2 pins are for a rear door mounted lock/unlock switches.
Or possibly I'm completely wrong...
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autostaretx
Erratic Member
No, the CTM looks at the feedback when it thinks all of the doors should be locked, and then fires a single "unlock" to all doors if any are seen as not fully "locked". It doesn't just grind the motors.
See the "dot" and "double dots" near the pins?
They're there to tell us that the pin numbers change between Cargo and Passenger.
MB wouldn't have put the door-side pins on Oxy's door if there weren't a reason for them.
(example: note the *empty* center pin position on the upper set on the door side.. that's where a van with heated rear windows would have a third pin (ditto for the lower set) to power the heater. And (on models with a security system) the rear window heater strips are used for glass-breakage detection.)
Since this van doesn't have rear window heat, MB didn't put in the third contact pins.
Each wiring harness is quite vehicle-specific (saves copper... hence saves MB money)
No, just not yet fully mugged by how MB thinks... you'll get there.
--dick