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Iwan's lc5

Can you diaconnect the existing pin 1 from the plug when you try your new wire?
Iwan, the security light is meant to flash with ignition off.
The light goes out when key inserted.
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Well have managed to get enough space around the loom now, have been attempting to trace the red with silver dot t9 1 which runs to the blue block connector holder in the kick panel.. This wire with the paper clip and yellow patch wire is dead, so the other end of the wire can't be identified... presuming the fault is inside of the cabin loom...

I'm thinking to start from the ecu b fuse under the bonnet and test the pins in the blue holder, if its found then can hopefully find the faulty wire in the internal loom by refitting the plug then cut the wire at both ends with enough length and fit a new wire in place of it... but if there's been burning then this area will have to be found in the loom to see what it's burning onto??? This is provided the under bonnet loom is alright!

Opening up the loom isn't a pretty sight! But leaving the damage in place could make the truck unreliable and make driving it an unrelaxed experience knowing there's a damaged area within the loom... :sweatsmile::sweat:

Will get out and have a good look for it! Lol
So, from the diagram, it looks like the wire goes from pin 1 on T9 to Junction Box 1. I think JB1 is the fuse box on the drivers side?

It goes from T9 pin 1 to 1D (connector D on Junction box 1) pin 4. It then comes out of 1B (different connector on same junction box) pin 3 and goes off to the next junction box (I - not sure where that is? - but enters on IL pin 4, leaves on IB pin 4 and goes to the ECU-B fuse)

Heres the diagram for junction box 1 - you should at least have continuity between the pins in the junction box. I've got a spare if its fkd


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Some clues on where IB might be.

I've got a piece of paper that says IL is 'Engine wire and instrument panel wire on left side of blower unit' - but cant find the pdf to upload.

I'm sure you'll have good access to that area by now :)


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Thanks man, I think I will look at junc 1 to check continuity to t9 1..

Just looked at the fuse box, it smells burnt around this area..

On a plus note have located the wire for ecu b no 2 fuse but not ecu b wire to fuse..

It's pretty full on inside checking wires!!
There's 2 junction boxes either side of where the passenger air bag is mounted. Similar to the last pdf, Has 20 pin then 4 no 10 pin connectors.
I *think* they're JB2 and JB3 - don't think theyre involved in your wire as far as i can see... Heres what I've got for them!


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Just looked at the fuse box, it smells burnt around this area..

Which one, the drivers side internal one?

I think there's relays on the back of that - possibly a burnt relay?


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Thanks man! Have just located jb1 it is very well hidden just above the steering support bracket with the cluster removed.. only to be seen through the windscreen outside!! So will check from here!!
jb1 d4 black wire... jb1 b3 purple white stripe there's no continuity back to t9 pin 1

As this t9 pin 1 has constant power and doesn't connect with any other circuits, as its a wire running solely to ecu b fuse ignition off power.. at present this wire is "absent without leave!" Being a broken circuit it's very difficult to trace...
So, just back to basics (for me)....

T9:1 -> JB1 D4 - continuity?

JB1 D4 -> JB1 B3 - continuity?

ECU-B -> JB1 B3 - continuity?
IT's a fair game this one and can safely say I'm wired!!! :laughing-rolling:

T9 pin1 Just haven't managed to get any continuity to any red wire either striped or silver dotted. on the inside wiring ..

With the JB1 block I just couldn't find the correlating red with silver dotted wire to be on JB1 D4 it was a all black wire, had checked T9 pin 1 on all of the jb1 block.. iirc there was/is and just checked 2 reds with silver dot in there..


This is how the JB's are constructed brass contacts and pretty solid state units. This is JB1. An after thought as there's 2 red / silver dot wires should find the bar and test continuity from this point to ecu b no2?? Solid connection and would show

Had a few attempts of finding ecu b 's wire entering to the interior to the molded blue block connector holder n/s kick panel... no continuity via testing with the paper clip... if you get the angle right it's akin to playing a xylophone as you're gliding past the pins lol, managed to find ecu b no.2 same technique red with blue stripe just as in the fsm. So thats marked up and has had a paper clip in it since discovering and as checking continuity would switch over to check via this one too as it has been proved to goto the power source and evidently works...

End of day have been attempting to split the under bonnet fuse box in a bid to get to the under side of ecu b and ecu b.no2 fuses to check condition and know the colour, stripes, dots etc. Looking at the fsm wiring charts haven't seen any mention of ecu b .no2 ??? Is there ecu b no2 fuse on a lc3 and lc4???

On the whole yesterday was a smoothe expedition in actually discovering the issue... but today has been a grind as in finding exactly where the problem is, it is a f'ing lot harder! LOL!!

I'm not going to give up on it but there's always the chance to buy a mot failure with working electronics to transfer into this one.. idealy to convert to a lc4 (05 onwards) and change the interior to a darker colour . A few breakers on ebay may try for a deal to buy everything from the inside and transfer over to this..

So just to summarise, you're not even seeing the wire physically go from T9 pin 1 to any pin in JB1?
At the end of the day though, all you need is a working 12 V to T9 pin 1?
Yep thats whats needed, ideally to isolate the faulty wire at both ends.. To eliminate future problems with it.
So just to summarise, you're not even seeing the wire physically go from T9 pin 1 to any pin in JB1?
Just had a very quick look at it now with a fresh head in the morning..
No continuity from T9 pin1 to any pin in JB1..
red wires on JB1
A4 and A14 block connector A (white) they're both inline together both red with silver dots..
B4 block connector B (black).. red silver dots..
E3 block connector E (white) Red with blue line.. just tested continuity with the diode sign and gives a buzzer on the multi meter.. E3 to ecu b no.2 (passenger footwell) and got reading 0.598. So there's a slight connection there and of course the change over from red silver dot to red with blue stripe which got es to the under bonnet fuse box... I missed doing this test yesterday. There's something to go by there..

Want to check JB1 E3 to the other reds without the plugs in, so to ascertain the original T9 pin 1 to JB1... Will do that after work as I'm late going to work now!! LOL

What did me in yesterday was that I couldn't find ecu b fuse thats next to ecu b no.2 which I've traced.. Which made me wonder if it's ecu b no.2 to T9 pin1???
Hmmm... !

I think I'd still be tempted to put 12V to T9 pin 1 (after removing the existing wire if you want) to check that what you're chasing here will actually fix the problem, once you do manage to get 12V.

Note that the wiring diagram I have says that the wire should be red and white - thats probably your red / silver though?

Weird that none of the colours are matching up to JB1 pins though isnt it! I was wondering at first if the A-E connectors were the other way around (so A was E, B was D etc) but as A is the only one with two rows of pins and you talk about A14 thats not the case!

Are you definitely looking at JB1? On RHD, JB1 is behind the cluster right?

Question on your multi meter - i dont think you should need to use the diode mode? And you say you get 0,598 - what does that mean - is that 0.5 Ohms? If so thats basically continuity right - its a fairly low resistance, unless your wire is very short.

For your last two points.... yep I think its better to check with plugs out - then you're just checking the wire and no chance of false readings due to the internal connections in the junction box.

Im a bit confused about the ECU-B and ECU-B No 2 fuses - are there two? My diagram says its 'ECU-B' but also has a number 2 next to it. Hmmmm

Let us know what you find!
Just doing a bit more investigation. Haynes diagram shows The ECU-B No 2 fuse, and that wire going to the DRIVERS SIDE FUSE BOX (not JB1)..... connector B4.

Then out of the fuse box on L4.

So that 'IB/IL' in some diagrams is actually the drivers side fuse box!

See attached for the fuse box diagram

You should be able to get to B4 without taking the fuse box out. I think L4 (even though its not on that diagram) is on the back side of the unit from what I remember....

Haynes then has it going from fuse box L4 to what its calling 'No 2 junction connector'. I dont know if this is possibly JB2? It enters on B3 and leaves on D4. It might be worth checking the wires on junction box 2 (in the middle of the dashboard I think)?

I've attached JB2 details - maybe those wires will match? I think we're matching together about 20 wiring diagrams from 20 sources, so they might be called different things?


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Correction, Haynes shows it going off ECU-B fuse, not ECU-B No 2

It is also W/R (white/red) wires.

I'll upload this haynes shortly