The system operates on nominally 433.98 MHz and the Gen 1 receiver was appalling, it would respond to any signal between about 425 and 440 and wake up the BeCM. I say nominally as external influences will affect the precise operating frequency so the receiver needs to be wideband to a certain degree. Just not as wide as that of the Gen 1..... The Gen 2 had much better selectivity so would only respond to signals much closer to the operating frequency but will still wake the BeCM upon receipt of a signal from any other licence free short range device in that band (433.05 -434.79 MHz). The Gen 3 receiver performance is pretty much the same but the difference is that it doesn't wake the BeCM until it sees a valid P38 code.

Marty's RF filter does the same thing, the receiver, irrespective of which one, receives a signal, instead of passing it directly to the BeCM it is passed to the filter which checks to see if it is a valid P38 code. If it isn't, it rejects it but if it is the code is then passed through to wake up the BeCM. All P38 codes have the same pre-amble before sending the individual code for the car so all will wake up the BeCM but only the correct, matching, code will turn off the alarm and immobiliser and allow the engine to be started.

davew wrote:

Well at least Mr. Griffith would be impressed you remembered the Inverse-Squared Law: Pity he was not able to explain that to LR 30 years ago as their RF Engineers were so bad.....

It was BMW at the time and the 7 series of similar vintage was just the same. The receivers were made for them by Siemens but made to a price. When I sent a report as to why they suffered it was passed through various departments before ending up at Siemens who's reply was "When you are only paying 0.09 Euro per receiver, you can't expect quality"

Yes, we can't see your Sooz pic

You can now, I've edited the post.

If you disconnect the blue antenna wire from the receiver, you'll need to be closer for the fob to work but it will reduce the interfering signal it it receiving.

I have the same, something my next door neighbour has will keep waking up the Ascot but not mine as the Ascot is a 96 with the early receiver, mine is a 98 but with one of Marty's filters on it. If I park mine nearest the neighbours house with the Ascot the other side of it, not a problem with either, if the Ascot is nearest the neighbours then the BeCM is constantly woken up.

davew wrote:

Richard, yes, and that's what I thought too... and that the Timer Relay was only supposed to operate for 20 seconds every 6 hours... under BeCM control...

No it isn't, the relay contains the timer (probably by a 555 timer chip or similar) and isn't controlled by anything else, it just wakes up. If you look at the diagram, it has permanent power on one side and ground on the other.

Chasman wrote:

Okay, removing the EAS delay relay stopped the cycling. Thank you!

That's odd, it's only supposed to wake up every 6 hours?

There shouldn't be. Radio has a permanent supply to keep the memorised stations, clock, alarm and that is about it once the BeCM has gone to sleep. That happens 2 minutes after no inputs to trigger it. Easy check you can do is to sit in the car at night. While the BeCM is awake, the red LED next to the gear lever position will be glowing very dimly while it is awake and will go out once it is sleeping. So if you get into the car, close the door, sit there watching the LED and you should see it go out after 2 minutes. If it is the BeCM being awoken by something, you will see it come back on again at the time the current draw would go up again. You can easily wake it at will if you have a keyfob for your other P38 by pressing a button on that. With a Gen 1 or 2 RF receiver, it will see the transmission from the other fob and wake the BeCM in anticipation of receiving a valid code, (which it won't get as the fob is for the wrong car) and that will start the 2 minute timeout again.

The SID gives a list of all the things that will trigger it and wake it up (or prevent it sleeping in the first place) so you can go through the flowchart and isolate which input is triggering it if it is being woken by something.

Yes it does work. A friend does mobile AC recharging and he has suggested it to a few customers that were in a similar situation to you and it has cured very small leaks. In fact, there's a can of it in Dina's Merc which had a very small leak from the evaporator and I think Merc started there and built the rest of the car around it making replacing it more than just a PITA. That was losing charge after a couple of months so if it can seal that it should do yours without a problem. Follow the instructions to the letter though or you'll end up getting covered in it.

Usual place for leaks on a P38 is the top corner of the condenser but with a leak as slow as yours, even putting tracer gas in and using an electronic sniffer it would be difficult to detect.

In my previous life before retirement, my work involved tracing this sort of thing. I would say that the BeCM is sleeping so you should have around 0.03A (30mA) but when it is awake it will rise to just under an Amp. For it to cycle it could well be something transmitting every 4-5 minutes so the BeCM sleeps, is then woken up, it waits then goes to sleep again and the cycle starts again. Favourite source at that kind of interval, would be the outdoor unit for a wireless weather station.

But, as Dave has said, the BeCM SID has a list of things that can wake the BeCM up and a flowchart to follow to identify what is the cause. I posted a link to it here https://rangerovers.pub/topic/3311-reconnecting-battery-alarm?page=1#pid40747

Open the door, open the bonnet, close the door and then reconnect the battery. As long as the status when the battery is reconnected (doors open or closed, doors locked or unlocked, etc) is the same as when it was disconnected, you shouldn't have a problem.

If the car is going to be left for any length of time, open the bonnet, then close and lock all the doors, disconnect the battery and close the bonnet. When you want to reconnect, open the drivers door (which, with the battery disconnected will be the only one that will unlock), open the bonnet, close the door and lock it, then reconnect the battery.

How much current drain do you have? Do you have the BeCM SID with the current drain diagnostic flowchart, if not, it's attached.
enter link description here

Info you need is from page 10 onwards.

The ABS system is a bit weird. You have to exit and reboot the Nano before it will connect a second time. That might be what you need to do between each step.

Did a bit of maintenance to mine today. A few days ago when summer arrived for a day or so, the AC seemed intermittent and would work better when it wasn't needed than when it was. Clutch failing to engage in warmer weather is usually a sign of the air gap being too big, and it was. A test for this is to put the HEVAC on Lo and look to see if the clutch has engaged. If it hasn't, a tap with a screwdriver handle will cause it to pull in. If it is only slightly too large, there's a shim behind the cover that can be taken out to get the gap back to where it should be. Tried the screwdriver tap. It pulled in but wobbled around all over the place. The air gap, which should be between 16 and 31 thou, was considerably larger than that and, pulling the front off showed it was so badly worn that while the gap looking at it from the outside was around 50 thou, it was so badly worn it was near double that at the mating faces. A quick look on eBay found a complete compressor for £35 so bought that and it arrived this morning.

Took the front cover off the replacement and it was fine, so was the face of the pulley where it engages. So out with the circlip and off with the pulley. Doing the same with the compressor still on the car isn't quite as easy as there's things like the PAS reservoir and a radiator in the way. PAS reservoir is easy enough but didn't fancy taking the radiator out or degassing and regassing the AC system (even though I've got the kit for doing it) so I could get the compressor off, so struggled a bit with the circlip. But once that was out, the pulley came off, replacement fitted and, even with the shim, measured the air gap at 22 thou so all good. Put the AC on Lo, and stuck my AC installers calibrated thermometer in the dash vent and ran it for a couple of minutes. Air out of the vents at 0.9 degrees C says to me that it's working as it should again......

Before you come to fit it, one thing I remembered from fitting mine was that the clamp supplied to join the left and right half's together was fractionally too big. They have a sort of spacer which I took out on mine so they would clamp up tightly. Getting both hangers on the silencers into the rubbers is a really fun job.....

No problem at all, they are all the same except for the cable length and location of the grommets. One of the rears on my Ascot died and, as it is pre-97, has the really long cables that run along the axle. I got a used Wabco, chopped the plug off and soldered it to the old cable, works perfectly.

Petrol is the same. With the coolant reservoir moved away and a bit of sqidging of the insulation it's a bit fiddly but can be done.

No, just the interior handle surround out, the switch just pulls out once that is off.

Simpler than the switchpack switches. You'll find that taking it out and squirting contact cleaner into it could be all it needs.

Have you got any diagnostics? If you have, what temperature is it running at? GEMS tend to run in the mid 80s C while Thor run a little hotter around 92-95C.

It was only a wild guess and it may well have been something else that you have disturbed but, if it is now working fine, that's good. I'd run it around for a bit before deciding you've fixed it though.

BECM - Diagnostics - Inputs - Mirrors Windows, three or four screens in you can see the status of the switches, so you can try the switch and see if the status changes. Then in BECM - Diagnostics - Outputs - Windows/Sunroof where you can operate each from the Nano.

To confirm it is the switch pack first and not the window motor itself. You should be able to operate the window with the Nanocom so confirm it does actually work.