Thank you sir! I'm going to do some track-and-reporting. Just got some blue MAXI fuses, that run the BECM and I will check with that first. If that reveals no joy I'm going to get that. Only £45.
make sure its the right part number there's lots of variations that look the same
 
If you are getting a crazy chatter of relays clicking, then it does sound like it might be POS I input to the BECM that is causing the issue.

The next step would be to check the continuity of the White/Pink wire (it's a thin one - not a thick one that carries 12V power) from the ignition switch (it plugs in somewhere under the steering column from memory) and ends up on pin 13 of the 16 way white connector on the BECM, which is under the fuse box. That wire should have a constant connection to ground when the ignition is in POS I or II.

If it's not there or intermittent then the issue is in that wire - I've had it before from a guy in the UK where the problem was an intermittent break in that wire in the loom where is runs in the sill (same area as you show in your pictures).

I'd add that to the list of things to check tomorrow... If you're unsure about it, then if you poke a wire into the back of the connector so it makes contact with the pin (with the connector plugged in) and ground that, it will mimic the ignition being in position 1. If you then turn the key to position 2 and it all works as it should, then you've proven the problem is on that wire somewhere. If it still doesn't work when you mimic position 1, then it points to it being internal in the BECM.

If I were a betting man, I'd say that the pos 1 wire has an intermittent break in it, causing your problem.
Got the dash apart and found said wire. Pushed and pulled on some things. Sometimes everything would stay on, then just go off again. Replaced the BECM underhood maxi-fuses too. I really don't want to take it to a shop if I can avoid it, the local land rover expert is fairly pricy. Any other ideas? It seems to stay on when the truck has warmed fully up after driving for a bit.
 

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On the under hood fuse box pull the relays out. And look for signs of browning on the relays or melting around the relay connectors .. it could be the under hood fuse box is failing. There are tracks on it which start to fail. Mine were most visible to the front of the fuse box.. nothing major just some light melting around the heater blower relays maybe the tracks are starting to crack up and expanding enough when warm to make the connection
 
On the under hood fuse box pull the relays out. And look for signs of browning on the relays or melting around the relay connectors .. it could be the under hood fuse box is failing. There are tracks on it which start to fail. Mine were most visible to the front of the fuse box.. nothing major just some light melting around the heater blower relays maybe the tracks are starting to crack up and expanding enough when warm to make the connection
Thank you sir. I'll check that now. I tried hooking into the pink and white wire and grounding that and no joy.
 
On the under hood fuse box pull the relays out. And look for signs of browning on the relays or melting around the relay connectors .. it could be the under hood fuse box is failing. There are tracks on it which start to fail. Mine were most visible to the front of the fuse box.. nothing major just some light melting around the heater blower relays maybe the tracks are starting to crack up and expanding enough when warm to make the connection
I checked and some were light brown. I have cleaned them up alittle. I'm going to do a test tomorrow after work, just to make sure it's when the truck is hot. That will limit it down to either something in the engine bay or maybe just a coincidence with the POS1 ignition wire.
 
the browning will be from high electrical loads. a sign that he fusebox is going to give problems
So more than likely the stuttering accessories would be the under-hood fuse box? It would make sense. I just don't know what do to do fix it.
 
The picture you show has 2 connectors in it, neither of which are the ones for the igntiion position 1 wire.

I've mentioned where the wire ends up on the BECM, have you tried testing the continuity along that wire back to the connector with the ignition switch?

If you can hear relays chattering in the BECM then to me it has to be something internal in the vehicle. If it we an underbonnet fuse box issue and dropout of power to the BECM then you would have other electrical things that are failing too, rather than just a few things not working like the HEVAC/Radio.

Igntion%20connector.jpg


Igntion%20connector%20BECM.jpg


For Reference, C0028 in the top picture is where the White/Pink wire starts at the igntiion switch, and C1280 in the bottom picture is where it ends up at the BECM. Only doing a continuity check on that wire with a multimeter (including wiggling the loom etc about a bit whilst the meter is connected) will be able to tell if there's a break in it somewhere.
 
The picture you show has 2 connectors in it, neither of which are the ones for the igntiion position 1 wire.

I've mentioned where the wire ends up on the BECM, have you tried testing the continuity along that wire back to the connector with the ignition switch?

If you can hear relays chattering in the BECM then to me it has to be something internal in the vehicle. If it we an underbonnet fuse box issue and dropout of power to the BECM then you would have other electrical things that are failing too, rather than just a few things not working like the HEVAC/Radio.

Igntion%20connector.jpg


Igntion%20connector%20BECM.jpg


For Reference, C0028 in the top picture is where the White/Pink wire starts at the igntiion switch, and C1280 in the bottom picture is where it ends up at the BECM. Only doing a continuity check on that wire with a multimeter (including wiggling the loom etc about a bit whilst the meter is connected) will be able to tell if there's a break in it somewhere.
Thank you for this. I will check this after work and report back.
 
The picture you show has 2 connectors in it, neither of which are the ones for the igntiion position 1 wire.

I've mentioned where the wire ends up on the BECM, have you tried testing the continuity along that wire back to the connector with the ignition switch?

If you can hear relays chattering in the BECM then to me it has to be something internal in the vehicle. If it we an underbonnet fuse box issue and dropout of power to the BECM then you would have other electrical things that are failing too, rather than just a few things not working like the HEVAC/Radio.

Igntion%20connector.jpg


Igntion%20connector%20BECM.jpg


For Reference, C0028 in the top picture is where the White/Pink wire starts at the igntiion switch, and C1280 in the bottom picture is where it ends up at the BECM. Only doing a continuity check on that wire with a multimeter (including wiggling the loom etc about a bit whilst the meter is connected) will be able to tell if there's a break in it somewhere.
So I did a check and the wire pulls about 10.7v, but when I turn the key into the accessory position, it drops all power. Is this normal?
See attached //
 
If it should be a live feed, the voltage is way too low then goes to nothing as load applied. Classic case of very high resistance as @martyuk said
 
If it should be a live feed, the voltage is way too low then goes to nothing as load applied. Classic case of very high resistance as @martyuk said
So should I splice into the line and run my own wire straight to the one in the ignition? Or does the problem lie elsewhere?
 
I'm not sure, simply because I don't have the wiring diagram to hand.
Basically, there is a wire with a very high resistance connection somewhere and when you load up the circuit, it pulls the voltage down to zero. Find the high resistance and make it good and the problem should be solved.
 
I'm not sure, simply because I don't have the wiring diagram to hand.
Basically, there is a wire with a very high resistance connection somewhere and when you load up the circuit, it pulls the voltage down to zero. Find the high resistance and make it good and the problem should be solved.
Would the high resistance be some where along the White/Pink line or in the same harness somewhere?
 
Thank you all for being so patient and taking me step by step through this. My mechanic wouldn't even touch this.
 
Sorry, I'm busy at work a lot of the time at the moment, and in a totally different timezone to the UK - so trying to catch up as/when I can...

The ignition switch doesn't switch a live feed, but rather it switches a ground signal. So on a multimeter, you possibly will see a voltage on the wire when the ignition isn't switched on, and it should go to 0V when turned on if it's connecting to ground properly.

That being said, depending on the resistance of the connection will depend on whether the ground signal gets to the BECM properly or not.

I would still be trying a CONTINUITY test ALONG the white/pink wire from the ignition to the BECM. Unplug the connector from the BECM with the White/Pink wire in it, and do the same at the ignition. If you have a digital multimeter with a continuity test setting (or beep tone - same thing, or if you don't have that function, then resistance check, on a 200 ohms setting) then (probably with a small bit of wire as a jumper to get into the pins) connect one probe to the ignition end, one to the BECM connector end. If it beeps and shows 0 ohms, then you have continuity and a decent connection. If you then wiggle the wiring, wiring loom in the sill etc and the meter stops beeping, then you have a break in the wire. If it stays beeping and the resistance is still showing near 0 ohms then chances are the wire is OK and the fault is elsewhere.

If you do that, then it will tell you whether the issue is in the White/Pink wire from the ignition back to the BECM. If the problem isn't there, then remove the meter probes, plug it back in, and then turn the key to ignition position I whilst listening down near the BECM to see if you hear a click of the relays when you turn the ignition on.

If the wire is working, then it does point to an issue in the BECM, or something that's shorting out somewhere and causing the chattering of relays that you hear when the problem occurs.
 
Sorry, I'm busy at work a lot of the time at the moment, and in a totally different timezone to the UK - so trying to catch up as/when I can...

The ignition switch doesn't switch a live feed, but rather it switches a ground signal. So on a multimeter, you possibly will see a voltage on the wire when the ignition isn't switched on, and it should go to 0V when turned on if it's connecting to ground properly.

That being said, depending on the resistance of the connection will depend on whether the ground signal gets to the BECM properly or not.

I would still be trying a CONTINUITY test ALONG the white/pink wire from the ignition to the BECM. Unplug the connector from the BECM with the White/Pink wire in it, and do the same at the ignition. If you have a digital multimeter with a continuity test setting (or beep tone - same thing, or if you don't have that function, then resistance check, on a 200 ohms setting) then (probably with a small bit of wire as a jumper to get into the pins) connect one probe to the ignition end, one to the BECM connector end. If it beeps and shows 0 ohms, then you have continuity and a decent connection. If you then wiggle the wiring, wiring loom in the sill etc and the meter stops beeping, then you have a break in the wire. If it stays beeping and the resistance is still showing near 0 ohms then chances are the wire is OK and the fault is elsewhere.

If you do that, then it will tell you whether the issue is in the White/Pink wire from the ignition back to the BECM. If the problem isn't there, then remove the meter probes, plug it back in, and then turn the key to ignition position I whilst listening down near the BECM to see if you hear a click of the relays when you turn the ignition on.

If the wire is working, then it does point to an issue in the BECM, or something that's shorting out somewhere and causing the chattering of relays that you hear when the problem occurs.
I did this, and it has good continuity. No clicks however. I am going to go for a test run today and see if I can get it to warm up.
 

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