Sliding Door Question - Wiring

alexk243

KulAdventure
I just had my sliding door off the van to insulate and add wood paneling. During that process I replaced the latch mechanism and the middle roller. It is back on the van now and function correctly (latches closed) and when I lock/unlock from the front the door locks and unlocks, however the rear arrow flashes indicating that a door is not closed in the rear. Could I have rewired it wrong? What is responsible for telling the car that sliding door is closed?

When I replaced the latch mechanism I had to take a small plastic sesnor and move it to the new one. It installed easily and seemed to function correctly. Other than that there are the two wires coming from the contacts and I forgot to take pictures of them and both of them seem to fit into either one... how do you know which wire is which? if my lock/unlock is working can I assume I got them right? (50/50 chance)

Thank you.
 

Nautamaran

2004 140” HRC 2500 (Crewed)
There are two wires leading to the lock motor (they switch polarity to lock/unlock the door).
Then there are two sense wires, one at the forward mechanism for “locked” and and another at the rear latch for “closed”.
If your slider locks/unlocks properly, you’ve got the two motor leads connected correctly.
But if the CTM can’t sense that the door is closed or that you have manually locked it (esp. with the key) then the other wires are disconnected or reversed.

-dave
 

alexk243

KulAdventure
There are two wires leading to the lock motor (they switch polarity to lock/unlock the door).
Then there are two sense wires, one at the forward mechanism for “locked” and and another at the rear latch for “closed”.
If your slider locks/unlocks properly, you’ve got the two motor leads connected correctly.
But if the CTM can’t sense that the door is closed or that you have manually locked it (esp. with the key) then the other wires are disconnected or reversed.

-dave
The ones going to the rear latch? I didn't think that one could be reversed... Maybe it's possible I installed it wrong.

The wiring colors don't match when connected... And the wiring diagram does not have the colors of the wires. How do you know if it's wired correctly with the door off the van?
 
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Nautamaran

2004 140” HRC 2500 (Crewed)
Have a look here: (Dick’s the man for this discussion)
https://sprinter-source.com/forum/showpost.php?p=722552&postcount=4


C1 is upper pins 1,2; C2 is lower pins 3,4. The wires indicated are the ones hiding inside the van pillar, so aren’t helpful...

On my slider, the upper pins are plugged into the Blue connector (larger BL, two W/R wires), and the lower pins plug into the Yellow connector (smaller Gr/Br, Y/Br wires).

And I see my memory was foggy... the “ajar” switch is combined with the locked/unlocked sense circuit, so if you knocked the switch off the forward latch you would disable both senses.

-dave
 
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autostaretx

Erratic Member
Dave's analysis is correct: if the ajar switch is askew, the Sprinter will be unable to detect the locked/unlocked state of the door.

The above diagram is with the door in the "ajar, unlocked" state.
Both the "lock sense" and "unlock sense" wires are "floating" (not tied up or down).

When the door is shut, the ajar switch closes.
That ties the "unlock driver +" (C1/1) feed to the locked/unlocked switch.
If the lock is in any state BUT fully locked, that means that the "unlock driver +" will be connected to "unlock sense" (C2/4)
When the lock is *actively transitioning to lock*, the "unlock driver +" actually goes *negative* (frame ground) and will therefore first pull the "unlock sense" wire down, until it finally reaches full lock, at which point the "unlock sense" wire "floats" (isn't tied up or down).
When the "fully locked" end of the motor's traverse is reached "lock sense " is finally pulled down by the (currently negative) "unlock driver +" wire.

When you ask it to unlock, the "ajar" switch still feeds "unlock driver +" to the lock/unlocked switch. But now it's a positive (+12) feed.
At the start (while it's locked) the "lock sense" wire will see that polarity shift. But as soon as the motor starts moving, it will flip the locked/unlock switch to the "unlocked" state, thus tying "unlock driver +" (positive) to the "unlock sense" pin.
The "lock sense" pin is now floating, and will remain floating until the door is next fully closed and fully locked.

When the sliding door is open, the pins staring out into empty space makes both "lock sense" and "unlock sense" float.

When the door is shut and the motor is *not* being actively driven, i'm going to assume (meaning: i haven't measured it with a voltmeter yet) that at least one end of the motor is held negative, and the other end may simply float. The motor is relatively low resistance, so the ajar switch will see that condition as "negative", allowing the "lock sense" and "unlock sense" to report what's real by being pulled down.

It's fairly common in electronics to have a "sense circuit" (like the lock/unlock senses) be lightly (i.e. via high resistance) "pulled high (positive)", with the expectation of a low resistance pulling it down to negative when the to-be-sensed state is present.

--dick
 

Nautamaran

2004 140” HRC 2500 (Crewed)
The wire (wires??) running into the latch are passing through the “door ajar” switch (shown as a dashed outline in the bottom left of the wiring diagram)

-dave
 

autostaretx

Erratic Member
This is the sensor in the latch. I feel like this may be problematic as it is the only part I replaced (the latch, not the sensor). Is there a way to test this? Should I show continuity in any state?
I would assume that that switch should show no continuity when just sitting out there,
and show continuity when the spring leaf is pressed enough to make the inner mechanism go "click"

--dick
 

Nautamaran

2004 140” HRC 2500 (Crewed)
I’ve never dug into the rear latch, but my impression from others is that it can fail/break if slammed.
Going by the wiring diagram, that is a normally open single pole switch, so should have continuity between the connector pins only when you squeeze it (these micro-switches usually make a subtle click as they change state).
If the connector pins don’t show continuity in either state then the switch/pigtail/connector is faulty.

You can trick the door into thinking it’s fully latched by shorting the connector that the switch plugs into... that will complete the latch switch segment (lower left in diagram) and allow the CTM to “see through” to the state of the door lock switch (at lower right).

-dave
 

Nautamaran

2004 140” HRC 2500 (Crewed)
I believe it will be fine?
With the connector shorted, the van will still know when the door is open (the pins will loose contact with the frame) but will be blind to it being slightly ajar (not fully latched). So not the ideal answer to your problem, but certainly a diagnostic work-around.
-dave
 
... Any idea where to get a new one?
Someone parting out a van. I got used door lock actuators including micro switches (although slider has separate switch) on this forum from MillionMileSprinter who had a part out van on the classifieds section. Since you only need the switch, a new one might not be that expensive, but the actuators seem to only come in gold-plated versions when buying new. Looks like the switch is $80 from Europarts.
 
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Nautamaran

2004 140” HRC 2500 (Crewed)
I just searched the Mopar number and found the same switch and pigtail was used in PT Cruisers (driver’s door lock) which broadens the Pick-a-Part options considerably?
 

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