Testing:

Orange and black wires are connected.
Maxi Fuse 2 intact.
Relay 2 works in Syckes-Pickavant tester.
Removing relay and jumping 3 and 5 runs pump.
ECU switch for another LRPN: ANR4499

About the only thing left that you haven't checked would be the pressure switch. If the pump needs to run it would be open circuit, closed when the system is up to pressure.

C141 Pins 7 and 9 open.

Gilbertd wrote:

About the only thing left that you haven't checked would be the pressure switch. If the pump needs to run it would be open circuit, closed when the system is up to pressure.

I have a Nanocom. Anything else I can check?

"Raise Switch" and "Lower Switch" both say OPEN.

Car is in Accss.

These values do not change if I select Standard.

What are they? Where are they? What does it mean if both are OPEN?

Raise switch and lower switch refer to the rocker switch. Nanocom takes a second or so to show a change of state so if you press Up or Down and hold it, you should see the display change from Open to Closed while you are pressing the rocker. Doesn't explain why the pump isn't running though.

My current hypothesis is that the ECU in the car is faulty.

The new ECU appeared faulty but actually threw an error because it's calibrated for a different car and the values were out of range.

I'm going to give it a fair crack of the whip buy reconnecting it then doing all the crap with the plastic rods. All without a working pump... Trolly Jack and my arms will take a hammering.

I assume running the pump with Nanocom does so with exhaust valve open so I can't cheat? Thigh it occurs to me jumping the relay might work as long as i monitor the pump so it doesn't overheat.

I also wonder if just copying the Access mode figures might be enough to kick-start things...

I've seen mention of a car that didn't want to play while sitting on the bumpstops, but once it was jacked slightly so the height sensors saw movement, it all burst into life. Jumping the relay, or turning the compressor on with the Nano, should build pressure. If you monitor the pressure switch while it is running, you'll see when it is filled (although you'll probably hear the pump starting to struggle anyway).

Both ideas noted. But things have moved on.

Switched back to new ECU.

1 Noticed some corroded pins on the old one I missed the first time because my work light is a bit directional.

2 Ran the pump for a minute with the Nanocom just to prove a point. Cycling through the INPUTS I saw Temp Sensor was showing HOT. Checked the pump - cold to the touch.

It was showing NORMAL earlier. I should keep a log because I'm not 100 percent sure which ECU I had in.

Thermistor in order. Arriving Monday.

Honestly, though. I'd rather get a Viair, ground the Orange wire and never go through this again. I know purists disapprove of this kind of thing, but with a duty cycle of 100 percent (not 15) and almost 4 times the flow rate it seems perfect. Some people worry about demand spikes at startup but anecdotally that doesn't seem to be an issue.

Cold pump with thermal sensor showing Hot says the sensor is fubar. I'd be inclined to short the Orange and Black and run it a bit longer (while keeping a hand on it to prove it isn't getting too hot).

Found the sensors on RS but there are 4 with no clue which to pick. 12v obv. Closed when cold. But what temperature?

https://uk.rs-online.com/web/c/switches/industrial-switches/thermostatic-switches/

This one I suspect https://uk.rs-online.com/web/p/thermostatic-switches/2532773/?sra=pmpn, or you could go for this https://www.ebay.co.uk/itm/264871750482 which claims to be the correct one.

I had already ordered from the eBay link but he's away and can't post until tomorrow. That's why I was hoping to get one from RS. I suspect the photo on eBay has been doctored to remove the numbers. I'll post here when it arrives.

Have you fitted one before? Getting the motor apart can be a real pita. I've seen one, on a Classic, where the sensor was attached to the outside of the back plate of the motor and connected to the Orange and Black wires externally. It was done very neatly and almost looked like it should have been there.

I know someone on this forum has a Viair, I don’t remember who, but I think he’s really pleased with it. All of us on this forum are on the purist end of the spectrum, we all highly favour EAS, but I don’t think upgrading the compressor will get you shunned.

Its MartyUK that has one
https://rangerovers.pub/topic/1801-eas-compressor-reed-valves?page=2#pid26834

Have a feeling someone else might do as well, but not sure who.

The Viair is only slightly bigger than the original (which was a Thomas pump and not Dunlop as some seem to think) so could probably be fitted if the box was slightly modified but Marty has used the vacant space next to the box. Wouldn't be an option on a LHD car but plenty of space on ours.

Okay. Definitely going Viair but skint at the moment.

Does anyone have a link to the pictures and tips for replacing the over temp sensor in the compressor?
I found a couple and it's a mess in there. Motor brushes exploding all over the place. Do you switch the sensor or the entire board?

In theory you just replace the sensor on the board but, as you say, the brushes spring out and are a real pain to get back in. I suspect that is why the one I saw had a replacement sensor mounted using one of the screws on the outside. I've only tried to take one compressor motor apart to replace a bearing and gave up on it.

It is handy that failure is open, giving the option of piggy backing a new one. Thanks for the help. I was a bit down about this whole thing as the car was just back on the road. I was excited and on my way to a track day for a ride in a 440BHP M3, so this hurt. There's another opportunity at Thruxton on Tuesday and I found a 3rd pump in the workshop with a working sensor I can cannibalise

The light at the end of the tunnel is back on ... might be a train though!

Gilbertd wrote:

The Viair is only slightly bigger than the original (which was a Thomas pump and not Dunlop as some seem to think) so could probably be fitted if the box was slightly modified but Marty has used the vacant space next to the box. Wouldn't be an option on a LHD car but plenty of space on ours.

You are referring to the 350C? I'm about to buy, so I don't want to get the wrong thing.