What year P38 is it?

If you have no messages on the dash, and it's not turning over then depending on the engine type will depend on what could be causing it.

Could be a sync problem, or could be a fuse box/relay/starter problem too, but a bit more info would help pinpoint it a bit more..

Yes, I have used one set of the Piher pots before (which also aren't working properly in this set of blend motors now - I had bought new ones which had the hole for the thumbwheel/gear, whereas the older version I had needed some modification for the thumwheel to fit, but it's both sets that aren't behaving now.

Piher trimpots are the type used in the original blend motors aswell - so these are replacements that are supposed to fit. The difference on the ones with the thumbwheel slot already there is that the wiper is offset from the RR ones - so instead of lining the marks on the gears up, you centre the trimpot and then fit the big gear in it's centre position to match.

I have that datasheet on the trimpots, and they even show a circuit in there about using them as a feedback circuit. My next thing I'm going to look at is the board in the HEVAC controller, but i'm fairly sure it must be something to do with the blend motors, as it's doing it on 3 different controllers, from various years/part numbers.

The wire might be a couple of things.. post a picture up and we can help identify it :)

I know a guy who repairs the window switches if they are intermittent or faulty... think he's got about 6 of them sitting on the shelf too. You keep your wood front piece as he just sends the actual switchpack to swap over

Just go plug the Grom in.. then you can get some music going whilst you work on the other bits, and we'll then know if it does just work on a DSP system (I'm 95% sure it will!)

Yes, they are linear pots, they seem to be the only type that people sell. If you want a log pot in this style, then they seem to be special order from the manufacture.

The pots I have that are playing up are brand new Piher PT15 NV15 10K ohm. They are carbon track, yes, but both versions I have are brand new, not pre used ones in trying to test.

The old ones in the other set of blend motors (that will calibrate) are the originals and test fine on analogue/digital multimeter.

I'll check the new ones on my analogue meter too, but I think it would be strange that at least 4 brand new pots from 2 different batches are faulty...

OK, re headlinings...

I've had a look, and on eBay, AS Trim do LR/RR headlining material, plus 2 cans of spray adhesive for £69.99. I've dropped them an email to their 'sales' address to see if they would offer a bulk buy discount, for material to do 6/7 headlinings (as a rough guide - if the price is right, would you be up for it too Smiler?) and adhesive.

I figure the least they can do is say no...

Depending on what they come back with, then I will also have a look at the Martrim page, and email them to see if they would entertain a group purchase.

I know 6/7/8 headlinings might sound a lot to do in 2 days, but if i strip the cards out of my 2 restoration P38's, then including the other one I already have, will mean I could possibly have 3 cards out and possibly partly stripped before we even start - which would speed things up and mean we could be stripping a headlining out of one vehicle, and then putting a completed one in fairly quickly.

I'm going to go with Black on my P38, and whatever is closest to the factory original colour on my other 2 P38's, is anyone else wanting a different colour, other than standard? I am guessing that the more we get of one colour fabric, the easier it might be to get a discount - but if people want different things, then I can at least give them a fairer idea of what we would be after, so that way I can get the wheels in motion.

Thoughts?

Might be worth clarifying at some point... or maybe Gordon knows if he's been before...

The petrol P38's, at least my Thor, has 3 springs on the throttle assembly - one on the throttle cable, to return it back to idle if the pedal is released, one on the cruise control cable to do the same (again if either of the cables failed that input would then release all tension) and then there is a 3rd spring on the throttle butterfly itself.

I'm just curious now :)

For those of us that haven't heard of the Throttle Safety Spring... isn't that what the P38 has anyway on the throttle body? It's sprung loaded so it's closed by default - if the throttle is released, or the cable fails etc, then the throttle plate will snap shut on the spring in the mechanism anyway?

Or it is this an EXTRA spring?

Don't be - it's obviously something strange going on, or the tolerance on the pots that I've got is too big, and thus they are causing the HEVAC to not see enough of a swing on the input to let it calibrate.

Today I tried a few more things, including trying to swap one of the temp blend motors to the distribution motor position, and that motor still wouldn't calibrate properly.

I took some voltage/resistance reading at each end stop compared to the one that did work properly, and there is about 1K Ohm difference between the old potentiometer, and the new one at one end of the travel - which at that kind of range is a fair amount, since the actual output rotation is just over probably 90-120 degrees.

So, I don't quite know what the next thing to try is...

Petrol P38's are a wire throttle cable from the pedal to the throttle body. Diesel P38's are drive-by-wire, and the pedal connects to a potentiometer which then feeds the engine ECU a position of the pedal

When you look at the oil bank website, it shows Swindon HWRC as being a place to drop off used motor oil, from personal use.

I've never been there before to drop oil off, so don't know if there is a limit or not... 5L sounds pretty minimal, considering the engine oil change on a P38 on its own is 6L odd!

Might have to check it out, maybe take a 25L drum and see what they say... if the protest I can just say that it's from one full service on my vehicle. Engine oil, transmission, difficult, transfer case must add up to near 25L....

OK, so that's 4 so far... and 5 headlinings to do..

The other p38 will roll if I pump some air into the tyres.. I'm tempted to get some manual inflation valves to lift it off the bump stops too..

Camping... not sure about that.. most of it is used. for their farming, and to be honest I don't have a lot of interaction with the landlord. Might the ok there cheap campsites around the Marlborough area if people want to do that..

Fluids etc.. I'm sure we can do a bulk buy
I'm not sure what the waste situation is, I have containers I have been collecting it in so far, but I should probably look at getting a drum and then when it's full of old oil, get it collected.

I have some taps for 20l containers, so makes it easy for distribution. A couple of measuring jugs and a funnel and sorted..

The disco can stay firmly where it is... Maybe we can turn it into a bbq stand...

Actually, you know what... they are...

The drivers side one has a bit of a fault in the motor I think, as I swapped that for one of the other ones in the tested set I have and the motor runs properly... bit swapping the pots out, and just doesn't want to know.

Going to try measuring the resistance or the actual wiring, and may even the current the motors are drawing to see how it compares with the other set.

Something tells me I'll still be stumped tomorrow...

Ok, so Winter Camp never happened - mostly because I didn't organise it...

Between being away for work, and freezing over an engine swap (Thanks again Sloth for the extra help!) and freezing again to do a dash out/heater core swap in between 'real work' jobs, winter has (happily) seemed to have drifted past us.. nearly..

So turning thoughts to 'Summer Camp 2017'...

1) Who's interested in having another get together/working weekend?
2) If you are interested, then what would you like to get done to your RR?
3) If we get lots of people wanting to do the same thing (headlinings seem to be a theme already I think) then do we want to see if we can get any deals on bulk buying of parts etc?
4) Are we all happy to convene at my workshop again? There will only be the one indoor bay this year, as one of my restoration ones is inside and being pulled apart slowly... but if we are happy to roll it in/out, then we can free up the second one.
5) Yes, the disco is still where we left it 9 months ago...

For those who haven't heard of the camp before - you can get the idea from the title graphic for the forum - at best we ended up with about 8/9 P38's there (including my 2 restoration ones) - and got a few bits done, and had some good laughs and food cooked by our resident chef...

I'll start up with the task list... I'd like to get my headlining done, and hopefully 2 more done if we are doing a whole load - for my other P38's as they will need doing at some point, and the restoration needs to start somewhere!

So I'd be down for 1x Black headlining, and 2x Cream.
I'm also hoping to have my spare ABS modulator rebuilt by then, and possibly swap that over.
Otherwise, I'll be happy to help others out - especially with electrical issues...

Anyone else?

Yes, I think the next 'camp' will be summer now... things got a bit busy over winter - that and I was recovering from a long 6 weeks away working, and Sloth and I were recovering from hypothermia after doing my engine swap in January...

Think I'll wait a bit for it to warm up again, and have a few days with a bit more chance of sunshine... which will be useful if we have a production line of headlinings being done!

I'm going to make a thread soon actually about ideas/dates etc for this years 'camp'... I think it was about this time last year that I was starting to think about it - so should really put some wheels in motion.. will only have 1 workshop bay this year, as my '98 is in the other half and I'm slowly starting to pull bits of it off, to strip it back to something of a shell, so I can then start building it back up...

Might have to try and con Sloth into doing a couple more sets of brake lines with me at some point too... ;)

Kunifer for sure... 3/16th rings a bell. Length - I think a 25'/30' roll should do it.. I can't remember the length roll I got, as it was about 5 yrs ago, but I had enough to do it all in the one roll, with a couple of little bits left over.

Sloth reminded me when we were talking about brake lines last night that you might want to check the condition of the flexi hoses on the back and be prepared to replace them too if the unions are seized, or if the lines are looking worse for wear.

Even though the pipe is 3/16th (again, from memory) the unions are M10 metric.

Did you get nuts with the ball joints? I'm not sure if they come with them as standard.

I'm guessing the finger condom has something to do with brake lines... if I were a guessing man... haha

I did all the pinout sheets for the DSP system when I first got my RR (Was it REALLY 5 years ago?!?) because I had bits of the system missing, or not working - and it was more actually to aid me in fitting an aftermarket head unit...

Believe it or not... I have never ACUTALLY heard a P38 DSP system working.... my one was missing the DSP amp, and my '00 Vogue had the DSP amp, but it's toast, and hence has got one of my DSP replacement amp boards... (which the wiring charts were helpful for aswell!)

The way I see it... if it's meant to be able to work as an CD Changer input, then I don't see why it shouldn't work plugged directly into the head unit, vs at the other end of a long bit of cable!

I had a look on the Grom website with the DSP adapter you linked to, and I can't even think about where you would hook it up to on a P38... as Sloth says, maybe more geared towards L322/(Maybe X5?) and saloon models - maybe they changed the audio systems so the DSP amp handled ALL the inputs and switching.. The P38 DSP does Nav, and phone (if fitted) but luckily for us, the front end of it is still fairly standard..

I wonder if some of the changes on the 322 were because they went to an all-in-one unit for radio/navigation in the dash, rather than separate like we have?

I'm still a bit lost... I personally don't think the people at Grom (though can't fault them for their service and trying to help) have seen a late model P38 Range Rover or the connectors it has.

Factory Navigation in a P38 feeds straight into the DSP amp - mute line and audio lines. It has no connection to the head unit whatsoever.

If you look at the front of the vehicle at the blue connector, you should see the same 8 coloured wires coming out of the wiring to the connector as are at the CD changer - there's no addition Nav cables etc.

I could be wrong as I've never seen the Grom units in person, but you should just be able to use the standard blue Rover connection cable at the head unit to plug it in.

Ok, so I have a weird one for you...

Working on replacing some potentiometers in some blend motors, so I can send them off to someone who wants a set. Replaced the pots, and set them up, checked resistance across the range of travel, and all good - nice and smooth end to end.

Hooked them up to a HEVAC controller to make sure that it was driving them properly and they would calibrate, and that's where the fun started. Distribution motor would calibrate, but the temp blend ones fail and then chuck up an error, saying the stall position is wrong. Look in the live values, and their stuck at a max of 75/76.

Figure OK, something must be up with these pots, even though they are Piher NV15's 10K ohm, as mentioned many places. Decided I'd swap them for an older set of (new) pots, which have a different centre - so needed to grind them out for the thumbwheel gears to fit in.. No trouble, I've done it on a set before, and they've worked fine.

Put the other set of pots in and the same thing happens... tried with 2 different heater boxes that I've reconditioned - so no sticky flaps etc. and a couple of different HEVAC controllers - same deal...

Here's the rub... I've got an older set of blend motors, with original (working) pots... put them on the same HEVAC controller, and heater box, and they will calibrate fine... sit them next to the new ones, and measure resistance range vs resistance on pot, and pretty much the same.. even if I tweak the new ones, so they are the same, then no difference when trying to calibrate.

I've tried swapping one of the motors from old-new in case there was something up with that which was causing the issue to do with stalling etc, and again no change.

I'm really at a loss now - they are pretty much, for all intents and purposes 2 sets of working (when checked on a multimeter etc) blend motors... any ideas on why set, on the same heater box/HEVAC controller won't calibrate the end points on the blend motors? I know they only use about 50% of the actual motor range, but seems happy enough on the other set of motors, with original pots...

I've now spend 2 days pissing about with these things, and not actually any closer to a solution...

Huh? DSP interface? for what?

As far as I was aware, the Grom plugs in instead of the CD changer - which in both DSP and non-DSP systems feeds into the head unit...

I don't see why would would need any additional interfaces on the P38... It sounds like they might be talking about an L322, as even on DSP versions of the P38, the CD changer appears at the head unit on the blue mini-ISO connector....

As I've posted before (and the reason my DSP replacement project works) - the Alpine head unit on the later P38's is EXACTLY the same between DSP and non-DSP systems. The head unit must detect on power up (probably on the communication line) the presence of the DSP amp. If it's found, it drives that - if it isn't, then it drives all 4 outputs to each door/sub itself, and all the audio control is done in the head unit... Either way, CD changer on a P38 goes into the head unit - NOT the DSP amp...