Central Locking/Electrical Fault

[Joe_W]

My trusty LC has recently developed a problem with the central locking. It is intermitent and occasionally goes back to normal but has more recently been consistent. I always use the key rather than the remote.

The symptoms are:

1. Doors unlock with key, when a door is opened all the doors then lock themselves. Once this happens the key will only unlock the door it is used in and not the central locking. This only happens when engine is not running.
2. Lock/Unlock button on drivers door consistently works.
3. When the interior light is switched this seems to operate the central locking?!
4. When locking the truck and central locking not working, the key still operates the immobiliser, turns off the interior lights and ignition barrel light.
5. The other day the speedo, odometer and rev counter stopped working. This then started working once one of the doors were opened and the doors locked as stated in point 1. The speedo etc also would cut in and out when I pressed the lock/unlock switch on drivers door. This has now gone back to normal and only lasted a few days.
6. Fuel gauge recently has been intermittent and shows empty with flashing fuel light. This then goes back to normal when restarting the truck.


Im sure its all related somehow but now need to get it sorted as its quickly becoming a PITA trying to get everyone in the truck when every time a door opens it then locks itself!

Soooo any wiring diagrams out there that someone could share? Also if anyone has experienced something similar or can share any suggestions on this it would be greatly appreciated!

Joe

 

[jibberjabber]

My trusty LC has recently developed a problem with the central locking. It is intermitent and occasionally goes back to normal but has more recently been consistent. I always use the key rather than the remote.

The symptoms are:

1. Doors unlock with key, when a door is opened all the doors then lock themselves. Once this happens the key will only unlock the door it is used in and not the central locking. This only happens when engine is not running.
2. Lock/Unlock button on drivers door consistently works.
3. When the interior light is switched this seems to operate the central locking?!
4. When locking the truck and central locking not working, the key still operates the immobiliser, turns off the interior lights and ignition barrel light.
5. The other day the speedo, odometer and rev counter stopped working. This then started working once one of the doors were opened and the doors locked as stated in point 1. The speedo etc also would cut in and out when I pressed the lock/unlock switch on drivers door. This has now gone back to normal and only lasted a few days.
6. Fuel gauge recently has been intermittent and shows empty with flashing fuel light. This then goes back to normal when restarting the truck.


Im sure its all related somehow but now need to get it sorted as its quickly becoming a PITA trying to get everyone in the truck when every time a door opens it then locks itself!

Soooo any wiring diagrams out there that someone could share? Also if anyone has experienced something similar or can share any suggestions on this it would be greatly appreciated!

Joe

Possibly a bad earth, I had a similar fault with the Central locking, although not so drastic, I found one of the courtesy/interior light door switches was not earthing properly, as the courtesy/interior door switches work on a switched earth system.

What I did. Switch all the interior lights on in the 'door' postion, (only the ones opperated by the door switches) including the tailgate, then make sure that each door switch operates the interior lights, the tailgate interior light switch is part of the tailgate lock btw.

 

[Joe_W]

Possibly a bad earth, I had a similar fault with the Central locking, although not so drastic, I found one of the courtesy/interior light door switches was not earthing properly, as the courtesy/interior door switches work on a switched earth system.

What I did. Switch all the interior lights on in the 'door' postion, (only the ones opperated by the door switches) including the tailgate, then make sure that each door switch operates the interior lights, the tailgate interior light switch is part of the tailgate lock.

Thanks I will give that a try!

 

[jibberjabber]

Thanks I will give that a try!

Your welcome, let us know how you get on.

Also, I think, there are other threads on here about the C/L malfunction.

 

[uHu]

I would check the cable harness to the driver's door. The cables going into the door will brake sooner or later, and that gives funny results depending on which conductor fails and which one connects to earth where the insulation is broken/worn.

 

[t1pper]

I would check the cable harness to the driver's door. The cables going into the door will brake sooner or later, and that gives funny results depending on which conductor fails and which one connects to earth where the insulation is broken/worn.

My thoughts same uhu, the cables in the door take a fair amount of work

 

[Joe_W]

I would check the cable harness to the driver's door. The cables going into the door will brake sooner or later, and that gives funny results depending on which conductor fails and which one connects to earth where the insulation is broken/worn.

Ok great thanks for the suggestion, I will have a look tomorrow. Do you need to take the door panel off to inspect?
Edit- Ive just found a good post on here which explains. Going to have a good look tomorrow and will post some updates. Cheers

 

[jibberjabber]

My thoughts same uhu, the cables in the door take a fair amount of work

Thats a good idea. You just jogged my memory, I had that happen to my last 80 over 20 years ago.

 

[Joe_W]

So had a bit of time today and did the checks you guys suggested.

@jibberjabber the doors seemed to operate the interior lights normally (I think!) Do the front doors only operate the interior light above the 2 front seats & the door lights. Then the rear doors and tailgate operate both.

@uHu I removed the door panel and checked the wiring loom into the door plus the connectors to the power lock switch etc. Everything was perfect except for a tiny break in the insulation in 1 of the cables but definitely not the cause of the problem. Put some insulation tape over the break just to be certain.

I did however notice a badly burnt out relay in the engine bay. Had a quick look on here and it appears to be the glow plug relay which seems to be a known fault. Ive disconnected it for the time being. I don't think this is connected to my other issue but glad I noticed it as it was pretty melted and not safe at all.

Im a little stuck where to look next....

Does anyone have a wiring diagram and locations of the components for the central locking system. It would be greatly appreciated!!

 

[jibberjabber]

So had a bit of time today and did the checks you guys suggested.

@jibberjabber the doors seemed to operate the interior lights normally (I think!) Do the front doors only operate the interior light above the 2 front seats & the door lights. Then the rear doors and tailgate operate both.

@uHu I removed the door panel and checked the wiring loom into the door plus the connectors to the power lock switch etc. Everything was perfect except for a tiny break in the insulation in 1 of the cables but definitely not the cause of the problem. Put some insulation tape over the break just to be certain.

I did however notice a badly burnt out relay in the engine bay. Had a quick look on here and it appears to be the glow plug relay which seems to be a known fault. Ive disconnected it for the time being. I don't think this is connected to my other issue but glad I noticed it as it was pretty melted and not safe at all.

Im a little stuck where to look next....

Does anyone have a wiring diagram and locations of the components for the central locking system. It would be greatly appreciated!!

I didn’t think the 100 series had glow plugs

 

[David]

I didn’t think the 100 series had glow plugs

It has them
https://www.autodoc.co.uk/denso/1665221

 

[Joe_W]

I didn’t think the 100 series had glow plugs

It was a relay just like this one located on the drivers side in the engine bay
https://www.landcruiserclub.net/community/threads/1hd-ft-glow-plug-relay-melt-down.148084/

 

[jibberjabber]

It has them
https://www.autodoc.co.uk/denso/1665221

The 1HD-FTE as fitted in the 100 has no glow plugs.

 

[Joe_W]

The 1HD-FTE as fitted in the 100 has no glow plugs.

My bad, seems to be the heater matrix https://www.landcruiserclub.net/com...eater-matrix-help-please.146870/#post-1429513

 

[jibberjabber]

My bad, seems to be the heater matrix https://www.landcruiserclub.net/com...eater-matrix-help-please.146870/#post-1429513

Even the intake heater matrix on the 1HD-FTE has nothing to do with heating with regard to starting, it is purely there for enviromental reasons.

This is quoted from one of @uHu posts in a different thread. Some of this quote is not relevant to this thread, but the relay that you have found burnt out could be the 'intake heater relay'

Credit to uHu.

"The intake heater is not required at any temperature, but if you still have this battery and alternator killer connected, it will come on with the ignition for up to 90 seconds if the coolant temperature is under 40 C. The light in the instrument cluster will not light up, normally. I've seen it on for a second when it's very cold outside, but the heater is always on for 90 secs at cold starts, summer or winter.

There is smoke from an old diesel like this, and the colder it is the more noticeable. The intake heater grid is not an aid for starting in the cold, it is purely an environmental device. The cold start is secured by the fueling of the injection pump, which will compensate for intake temp and coolant temp. When it's really cold, it will do double squirts, which is noticeable as a "funny" combustion sound.

When you say perfect spray patterns and pressures, be aware that there was a change in both between the early years with the 4-speed auto and the later years with the 5-sp auto. The diesel workshop that I used didn't have that info and I had to get it from the FSM, when I changed my nozzles.

If the smoke is really bad, worse than other HDJ100s, you might have a valve or a sensor which is slightly out".

 

[Joe_W]

@jibberjabber Your right, after reading that post that makes sense and looking at the photos confirms that it is definitely that relay. I think I will leave it disconnected and not bother replacing with the info on here.

Now to find the original problem

 

[jibberjabber]

So had a bit of time today and did the checks you guys suggested.

@jibberjabber the doors seemed to operate the interior lights normally (I think!) Do the front doors only operate the interior light above the 2 front seats & the door lights. Then the rear doors and tailgate operate both.

@uHu I removed the door panel and checked the wiring loom into the door plus the connectors to the power lock switch etc. Everything was perfect except for a tiny break in the insulation in 1 of the cables but definitely not the cause of the problem. Put some insulation tape over the break just to be certain.

I did however notice a badly burnt out relay in the engine bay. Had a quick look on here and it appears to be the glow plug relay which seems to be a known fault. Ive disconnected it for the time being. I don't think this is connected to my other issue but glad I noticed it as it was pretty melted and not safe at all.

Im a little stuck where to look next....

Does anyone have a wiring diagram and locations of the components for the central locking system. It would be greatly appreciated!!

Did you check the cables between the 'A' piller and the door, they travel through the rubber sleeve just above the bottom hinge (I think this what uHu was talking about) and as the drivers door is the most often used the wires tend to get bent/stressed more often.

 

[jibberjabber]

@jibberjabber Your right, after reading that post that makes sense and looking at the photos confirms that it is definitely that relay. I think I will leave it disconnected and not bother replacing with the info on here.

Now to find the original problem

I discon mine years ago with no probs what so ever.

 

[Joe_W]

Did you check the cables between the 'A' piller and the door, they travel through the rubber sleeve just above the bottom hinge (I think this what uHu was talking about) and as the drivers door is the most often used the wires tend to get bent/stressed the most often.

Yeah, unplugged them and took off the rubber sleeve to have a good look and everything was ok. I will do the passenger side tomorrow I think

 

[jibberjabber]

Yeah, unplugged them and took off the rubber sleeve to have a good look and everything was ok. I will do the passenger side tomorrow I think

Good Luck and as they say 'Happy Hunting'.