As Mad-as says... I've pulled a number of the heater boxes apart and freed up the flaps in them. I usually ream the holes out in the heater box itself to give a bit more clearance for the flaps to move in, and also I've found in a number of them that the grease that was used originally had dried up and also instead of keeping things moving nicely actually helps bind things up.

I use silicone grease when putting them back together, rather than the white lithium grease (as it seems to get less greasy and more solid with age).

Also worth checking the alignment of the gears on the main grey spindle, as if they're out a bit then one set of the 3 flaps will get to the end of motion before the others and stall the motor out.

I've also found on a few heater boxes that the drive shaft from one of the sets of flaps has slid out over the years, so one set of the distribution flaps isn't driven properly (if at all).

Incidentally - the last few heater box out/heater core/blend motor swaps I've done for other people have been on later 2000/2001 vehicles and the heater boxes haven't needed any work and seemed a LOT freer than earlier ones. So I wonder if there was a slight modification in the production on them, as the later ones did have a different part number....

I believe you should be able to move ALL of the flaps (including the distribution flaps from one end to the other) with your little finger. The motors have a fair bit of torque in them due to the gearing, but obviously the freer the flaps, the easier life the motors have. I've managed to get some of the earlier heater boxes to be pretty freed up - but a couple of the later 2000/2001 versions that I've pulled out have been really free and easy to move - which makes me think they must have adjusted the tolerances in later production.

I can also vouch for the PAC SWI-RC - used one in my P38 for years until I went over to using the Android head units, which interface directly to the steering wheel controls.

When I was doing some decent mileage in the RR - I would get 75-76L into the tank, and around town I would get between 190-200 miles from a tank, depending on whether it was short hops around the city, or slightly better runs with less traffic, some dual carriageway etc.

On a full motorway run, when I would travel to Windsor and back a few times a week for work in October (ok, so 2019 was the last time I was doing that) I managed 243 miles on a tank - twice... it cut over to petrol at the same roundabout.

My best ever was about 256 miles out of a tank, but that was all motorway driving about 70mph, pretty constantly.

That's pretty much what happened to the ones I tried - but figured as they were already knackered, with the glass in bits, it was worth a go.

Weather out here is nice... though almost too hot at times - especially when I was working outside for 7 hours today... .but I definitely have a tan now!

I genuinely do miss being at home with my own stuff around me and the RR to drive - but the work is keeping me going, as I'd have been even more crazy than I already am if I was sat at home still with no work!

I have tried splitting some before as I had a set of 2000MY black insert ones with broken glass that an owner gave me, and a set of pre 2000 ones which I figured I could try swapping the glass over on.

I tried putting them in the oven, but obviously didn't get it hot enough or evenly enough, as I had the plastic surround crack aswell. I found it to be pretty brittle when it gets warm - or maybe as I say, the oven wasn't hot enough or I didn't leave it in long enough to get the sealant loose enough for it to release cleanly.

I tried with a hot air gun and it was even worse - as I couldn't get even heat around the glass, and it just destroyed the plastic surround.

As mentioned - highly unlikely it's the BECM as it just powers the HEVAC, which if it works otherwise, then it's unlikely to be that.

As Sloth mentioned, it's far more likely to be an issue with the wiring to the HEVAC. It has no load sensing on the outputs to the heated front screen or heated seats as it's just controlling relays. So if it isn't turning them on, then it's down to the HEVAC not getting the engine running signal.

Whilst I believe this comes from the BECM, it's unlikely (but not impossible I guess) to be an issue there, as the BECM also sends engine running speed out to the instrument cluster.

I'll try and have a look at wiring diagram later and see if I can give wire colours to check for the engine running signal to the HEVAC.

Also, make sure that your alignment is done with the vehicle at standard suspension height - the steering geometry changes as the suspension is raised/lowered and the wheel will be offset a bit in one direction or the other (which is normal) if the suspension isn't at standard.

I'm pretty sure there's a note about it in either the owners manual or RAVE mentioning that the alignment should be done at normal suspension height.

Hmm, odd... The server is still running as I can access it via my VPN... I'll have to check the links as I did have to update the web server software awhile ago and it typically broke a few other things that had been working. I thought I had got them all sorted, but maybe not...

As long as you're careful then they are easy enough to pull apart - I have done loads of them to LED convert them etc.

I also have the tools to reprogram a cluster mileage and the BECM mileage. It's just a case of having an EEPROM programmer for the cluster, and knowing what format the mileage is stored in.

The BECM can be reset a couple of ways, but I won't post that on an public forum ;)

But needless to say, it's not the doom and gloom that a lot of people make it out to be. It isn't the easiest task, as it requires some de-soldering of the chip in the cluster - but I've done a few mileage corrections for people over the years who have been told it's fine to just swap the cluster, and then wondered why their mileage suddenly spiked!

As Brian says...

The shorting pins are there for when they are unplugged, and then the connector housing moves them when the connector is plugged in.

The pins on the SRS connectors are a bit weedy, and they seat connectors can come loose pretty easily. I've had success before with wrapping a cable tie lengthways around the connectors when they are connected and tightening it up to keep them from wiggling around and causing spurious faults. But replacing the connector will do that too :)

It hasn't been updated. It's another one of the things that has been wrong for years.

I got in touch with BBS on the Nanocom forums years ago about the ABS labels being wrong and what they actually corresponded to. They said they'd look into it for the next firmware release and never did anything about it.

I found the HEVAC one a couple of years ago when I started refurbishing HEVAC controllers here and bench testing them, but never bothered to update BBS about that, given their lack of caring regarding the ABS one...

Pollen filter housing - or a buildup of leaves etc in the drain from the plenum can cause water to seep in aswell.
When sealing up the plenum, I find taking it all apart to the point of unscrewing the pollen filer housing and folding the rubber gasket back to clean under it and running a bead of sealant around there also helps.

I recently sorted water ingress for an owner where the issue was water leaking in from the top of the windscreen (it was factory original!) - there was obviously enough of a gap in the sealant that was allowing water through, where it then ran down the A pillar and into the sill/footwell.

Pretty sure most of the AEB based systems you press and hold the changeover button for about 10s will then force it to start on gas.

I don't quite get how you've got to leaky injectors. Unless you've pulled all the plugs and found that there's loads of excess fuel in the cylinders without having turned it over? But I haven't seen mention of that.

There isn't a NRV in the fuel line or fuel rail on a Thor - it's a returnless system that's pressurised by the pump and excess pressure is bled off in the pump in the tank. Different to the gems systems that have a return line and pressure regulator on the fuel rail.

Means that it's not seeing a change from the FR height sensor when it's commanded the valve to open.

It could either be a sticky valve, bad solenoid coil, or even a bad connection between the driver pack and the solenoids, or the EAS ECU and the driver pack.

I've seen a number of times where people have found loose pins in the connectors to/from the driver pack which gives a weird response, so I'd have a look at that first.

Worst case the driver pack is failing on that corner.

In that case, it does sound far more like a fuel delivery issue - where that be a bad relay, (or fuse box even?) Or maybe the fuel pump itself is starting to get weak.

Definitely worth checking fuel pressure.

If you're registering rpm when cranking, then I would think unlikely to be crank sensor - it is a common culprit, yes, but if you get a reading and playing with fuel pump on/off made a difference, I'd definitely investigate that first.

As Sloth mentioned - on a Thor, it will crank all the time, it just won't fire if it's out of sync.
GEMS petrol are the only p38's that won't crank if it's out of sync - EDC and Motronic will always crank, as the immobilisation strategy is it same, and the engine ECU doesn't respond to the BECM on accepting of a correct code like the the GEMS will.

Another +1 on the crank sensor though. In Nanocom/Motronic and maybe inputs/general 1 or 2 (could be wrong but it's in there somewhere!) there's a 'tooth count' parameter, which shows how many counts the ECU has done from the crank sensor. If this isn't registering counts, then it's not seeing anything from the sensor.

If you're passing Swindon at all then let me know and I can hook it up to my Nanocom

If anyone is around the Swindon area and wants bushed pressed, then I have a 20T bottle jack press and the correct tool to do it.

The tool was about £80 when I bought it and does the job nicely. I've done a few sets on my own without help, and it takes a bit longer to get it all lined up but once it starts pressing, its fine.

Yeah, she was a trooper alright... did a lot of km's in that RR before I traded it in for the '98 HSE... which had 18" Mondials on it, and was Cobar Blue with lightstone interior:

I think they must have been an option...

These were the standard 16" wheels on the P38 - this was my first one back in NZ, which was a 1995 4.6HSE with 16's on it: