[SthglosHI]

Yeah me too, it was never going to be that simple my luck just doesn’t go that way.

next weekend’s job is definitely to try to jump lead the solenoid, fortunately I bought a power probe tool a few years back hoping this makes that an easier feat.

in the meantime, new window regulator carrier plate on order, along with a new old stock 4589462AG lock mechanism. The lock is a 6 pin not the same as the US model, if you have an export model RHD do not mistakingly buy the 3 pin mechanism.

this is by far turning out the to be the worst repair job I’ve had to do. Wife is now resolute it’s time to get shot of it, she is of course right but pride won’t allow me to accept defeat 😬

 

[Nitrogen]

first job i had to do on my Nitro was mess around with the door locks, and it was a pain in the ass, and what a strange design the carrier plate is,
anyways the deadlock system is activated by a small soloniod within the locking mechanism and i don't believe there is any way of disengaging it other than with a 12v supply,
maybe with your new lock you can work out a way of pushing and proding something that will unlock it,
just remember to service the new lock before installing it, and it should be trouble free after that,

 

[Nitrogen]

looking at some advanced wiring diagrams curtesey of ScarO, and it has fuse J11 marked as Thatcham relay lock feed, the wiring is for several vehicles and the Nitro is listed as one of them, i doubt it is your issue but definitely worth a check,

 

[SthglosHI]

Thanks buddy, J11 tested as ok. I got all excited for about 10minutes until it was tested.

One thing I did work out though is the bullet connector, the associated harness, white multi plug and the rectangular black plastic box behind the metal bracket, are all part of the originally installed parrot hands free system that was in the car when I bought it. It was spliced into some vehicle wires that ran down the floor by the side of the removed driver’s seat. Thats a removal job for when the door is fully sorted.

 

[Westy52]

Hi guys, ok so yesterday i went to get in the nitro, it was very cold and the car was white with ice, so i blipped the button to unlock, all the buttons popped up and i tried to open the drivers door, but with no joy, ahhhh frozen shut, i thought, so round to the passenger side and it opened no problem,
in i got, climbed over to the drivers seat (not an easy task in a nitro) and tried the door from inside, with a pull of the handle and i bang on the inside of the door, but still nothing.
so i drove the car to work, with the heaters on full for about half an hour, got there and still stuck shut, climbed over to the passenger side to get out, and left the car sitting in the winter sun all day,when i finished work i thought, ok it will open, but guess what :i_rolleyes: still stuck solid.
ok, so what now, i put the car in a heated garage over night, tried it today, and still nothing.
so a phone call to dodge, and a few hours later they have the car.
but they are not looking at it till tomorrow, but the guy in the office did say that the dead lock can jam on...... and there was a procedure to get it off without stripping the door down :thk:

does or has anyone else heard of this?????
sorry for the long post but i was bored and wanted a good old rant

i will keep you all updated when i get it back...
i might even find out what the procedure he was talking about is

oh i did also ask them to look at a misting up front fog light, and the hand brake gaiter is burst ( so we will see what they say about that too)
oh and the electric cooling fan has a mind of its own, it comes on and off for no reason.

cheers
scott

This has happened twice to me - just undo the plug/wires on battery and it resets and door opens !!

 

[SthglosHI]

Yep a hard reset is the go to starting point for most things that go wrong. Been doing this loads of times over the years and it usually works. However, not this time. I’ve now done it 6 or 7 times over a few days and still the latch is deadlocked.

having owned it for the 11 or 12 years the only other time I had door locking issues it was a bad TIPM. Since that was replaced with most recent modification everything has as sweet as a nut.

Now the door is all now stripped down internally the next job is to use a power probe on the door latch connector pins with the wiring harness disconnected. See if that will operate the solenoid to unlock it…if not then the only other option is go in heavy to break the lock mechanism

thankfully I’ve found a new replacement RHD latch, fingers crossed it turns up in the post

 

[SthglosHI]

Continued to work on the door today, bought an old wiring harness with correct 8 pin (6 wires) connector for the door lock actuator. Cut the plug leaving 12” of harness so I could bare the ends to go to work with power probe. This allowed the disconnection of the installed harness to eliminate back feeding any wires by mistake.

tested all pins in accordance with available wiring diagrams. This is a bit hit or miss as the wiring diagram does not show the thatcham 6 wires, only the 4 wires for the US model. Nevertheless I was able to determine the lock mech was locking/unlocking as it should but the deadlock was seized. The door still wasn’t budging.

without being able to open door I wasn’t going to be able to change the lock actuator, so the decision was taken to try to break the lock working from the inside of the door.

this is tight for space and required a work light to see exactly what I was doing. I also used a Borescope from work to get deep look in and around the mechanism.

the backside of the mechanism accessible shows a white plastic casing. This casing covers the two motors, one at the top and one at bottom. With sections of this casing removed I was able to see that the bottom motor was soaking wet and badly rusted. By pulling out the two connecting wires enough to apply 12v, the motor was unresponsive and tested as open circuit. This motor was shot. These motors have tiny drive shafts with brass worm gears on them which in turn rotate plastic gears.

the top one locks/unlocks the mechanism as it rotates to and fro. I determined the bottom one did the same as the secondary deadlock. This bottom worm drive shaft was bent away from the gear. voila, the door opened.

with the door open I was now able the remove the three torx screws from the door shut, and the mechanism came out.

Now the next problem…having scoured the internet for part number 4589462AG I found only two suppliers claiming to have stock, unfortunately both cancelled the orders saying they could not source it. The part number is critical to the export RHD with the Thatcham security system, the US part will not work as it has less wires connected through a different mechanism connector.

The Nitro will now remain off the road until a replacement mechanism new/or recycled can be found.

So why did this happen, from what I can work out it due to the ingress of water from the ageing weather seal allowing water to run over the lock mechanism. If you’re lucky it won’t penetrate the mechanism. If unlucky like me water will get inside the mechanism and fill up around the bottom motor causing it to fail as mine did.

For the sake of less than £100 replacing a worn out weather seal it may just save the lock mechanism from suffering the same fate again.

For now the Nitro is having a well earned rest until a new lock mechanism can be found, if anyone has a RHD front right door working lock mechanism please let me know. 👍

 

[Nitrogen]

well done,
i didn't want to say anything else, in my mind i thought this could get a whole lot worse, ie: end up with a badly damaged door, or worse the fault was your new TIPM relay, however glad you opened the door,
the last person i remember had a big job chipping away at the lock mechanism until the door opened,
great info about the cause of the problem, nobody ever posted why the lock failed,
there is a chrysler, jeep, dodge breakers yard in the uk, last time i spoke to them they had plenty of nitro parts, can't remember there name but will try and find it, there must be a new mechanism laying on a shelf somewhere, finding it could be harder than unlocking the door, but fingers crossed and all that,

 

[SthglosHI]

Door finally open.

Door lock actuator removed (part number 4589462AD, latest revision is AG)

Bottom motor location nicely coated in rust from the motor sitting in a water bath

Bottom motor removed, this doesn't just happen over night. It's clearly been soaking for a few years.

 

[Nitrogen]

great pics, i can see what you mean now, what a stupid design,
i think i might just pull the fuse on my deadlocks, so i don't have this issue, plus i don't need that added security where i live, there are more cows than people around here, i really only lock the car if i'm in town,

 

[SthglosHI]

A precaution is always a wise move, given the ridiculous design of this latch.

from what I’ve worked out the non Thatcham door mechanism has only 4 wires.(earth, door ajar, forward and reverse feed wires for the single motor inside). By looking at pics of the latch you can see it has no second motor (bottom motor). The only wiring diagram available supports this, we don’t have the thatcham door latch connector wiring diagram showing the 6 connected wires.

the 6 wires are; earth, door ajar, top motor forward and reverse, bottom motor forward and reverse.

by a process of elimination it’s obvious the bottom motor is the deadlock motor. As it seems to enjoy sitting in a water bath it’s a matter of time before it fails. Totally agree it’s a stupid design to add to the other list for the Nitro.

if I can’t find a replacement 6 wire mechanism in a reasonable time I may have to consider getting a non Thatcham, the matching harness plug, and rewire the door. Not sure if this will work electrically by leaving the bottom motor wires disconnected, but it may be my only option worth trying. I guess there’s a chance it will throw up a body fault code.

 

[SthglosHI]

All four door lock mechanisms are deadlocking latches with two motors, therefore the secondary relays in the driver’s kick space activates/deactivates all four deadlocks not just the driver’s door.. the fact that all the other doors operate fine eliminates the relays as faulty. The fault could only be in the door wiring harness or the latch mechanism. So rewiring the driver’s door to allow the non Thatcham latch might work.

this is where my head was at before Saturday’s destruction of the latch mechanism. As usual my brain goes into overdrive with fault diagnosis like a dog with a bone 😁

The Nitro has tried many times to defeat me over the years…it sure as heck isn’t this time😜

 

[SthglosHI]

Well this is interesting.

A second hand replacement was found in breakers yard and delivered today. On examination the corner of the replacement latch where the secondary deadlock motor is located is shrouded in a black bitumastic type tape. I initially thought this may be some DIY botched repair job, but no it’s not…having found a number of pictures of ‘AG’ revision door latches they all have this rather dodgy looking tape attached.

Could this be a factory fix for the water bath problem. If it is, then to me it just looks like a cheap trick to stop the ingress of water, and definitely not what one would consider a professional engineered solution.

Apparently the breakers yard says it has been tested as working properly. We’ll see when I install it this weekend.

oh and by the way…anyone else looking for a replacement with the Thatcham deadlocking. The part number is P04589462AG, you typically don’t need the ‘P0’ when ordering. These are available new from Dodge dealers in the UK, at a costly £160 they also claim it must be factory coded to the VIN. I can’t for the life of me see how the latch could be coded, but I’ve heard this crap before when items were simply plug n play I.e. tyre pressure sensors. There are only a few Dodge dealers left in the UK, but they do exist:

I’ll post a picture of this sticky tape tomorrow

 

[SthglosHI]

black mastic tape mentioned in previous post