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I am wondering whether someone would be able to explain the differences between the diesel and petrol fuse boards ?

I have been offered a new, old stock, diesel fusebox for my diesel 2001, 2.5 DHSE by a closed down RR dealer in Liverpool. I know the chap from many years ago and I know that I can trust him. He closed his business about 10 years ago and he rang me to say that he has this fusebox in his garage and would I be interested. I am thinking that it would be a good idea to keep a brand new fusebox in my garage for the day when I need to replace my own one.

The problem is, having spent a good while looking on the world-famous Internet I can actually only find two different fuseboxes/boards, one for a petrol and one for a diesel engine. There are some second hand units on Ebay and they all seem to be described differently - one for a 1999 - 2000 diesel; another for all diesels; another for all petrol engined P38's. But Rimmer Bros lists the same board for all the diesels !!

Looking at pictures of one on Ebay they all look the same, so I can only think that the difference maybe the fuse sizes, and what they are connected to, thereby suggesting that the basic fuseboard is actually the same in all P38's. I wonder whether anyone can explain the difference between them ?

Pierre3.

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Rimmer Bros are a bit thin on P38 Fuse Boxes but go to the Island 4x4 web site and you’ll see that there are three Fuse Boxes listed for a diesel P38 depending on year/VIN. There are obviously differences as the part number changes but what those differences are exactly is a mystery unless the internal circuit board diagram can be found. It would be a brave man to try and fit the wrong part number!

I imagine there may be more differences between the diesel and petrol versions for obvious reasons and there are two versions (nominally GEMS and Thor) listed for the petrol version. It would be a very brave man to try a petrol version in a diesel (or vice versa).

In other words I would make sure the part number matches your VIN!

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I have just had a look on the Island4x4 website. Later diesel fuse boxes are £151 and £175 for genuine. Earlier fuse boxes are £600 ! all plus VAT of course. The petrol fuse box is listed as £1000 !! What the difference is I don't know.

There are different things plugged in under the bonnet such as the FIP stop solenoid and the relay for the glow plugs which is actually external to the fuse box.

I believe the early fuse boxes were made by Lucas, probably exclusively for the p38, while the later ones were made by Bosch. Maybe these were shared with a BMW car of the same era.

If you enter your car details into Microcat it will tell you the exact part number for the fuse box. It is good to have a spare as they do go.
If he has the correct one I wouldn't pay more than half the new price. Also no VAT.

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Thanks for the information, you guys !

I think that the fusebox may be similar to the power steering pipes - I bought a high pressure power steering pipe, listed for the early diesel P38. It turns out that it is exactly the same as the later, NLA, power steering pipe !

But I would agree with Garvin, there must be some differences or they probably wouldn't have different part numbers. But I wonder whether the petrol engine fuseboards are technically all the same, perhaps with a few small differences in connections, and that the diesel fuseboards are also all the same, but with a few small differences. I can imagine that if LR added, for instance, reclining rear seats then the fuse board could perhaps have an extra fuse and connections, but again, most of the internal car electrics seem to be powered from the board under the drivers seat.

I wonder, if I compare and count the fuses and relays, and they are all in the same locations then I can assume that the new board that I have been offered will, in fact, fit my car ? This is solely based on not having the correct part numbers to hand, for the new board and my own board. There is obviously only one way to find out - I'm going out to look into my fusebox and see if I can find a part number - that would confirm any questions.

Pierre3.

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There's 3 main part numbers for the diesel with superseded part number in between. The original one from 94 up to end of 97 year, was AMR3376, which superseded to AMR6406. AMR6477 was used on 98 models but the earlier ones also supersede to that number so an AMR6477 can be used on all models from 94 to end of 98 model year. The changes on these will almost certainly be the same as similar changes to the fusebox for the petrol models which was beefing up some of the tracks to prevent then burning out. 99 to 01 model year use the YQE103420 while 01-02 models need the YQE000010. However, the wiring loom for an 01-02 car is different to earlier ones so chances are that the outputs on the underside of the fusebox won't be compatitble.

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Richard, very many thanks for your information. One thing that interests me is that the fusebox that my contact has is the one that you list as YQE 103420, and I notice that on the lid of my own fusebox LR printed that the actual box and lid assembly is YQH 101060, and the two fuseboards are as follows:
Petrol - YQE 103410; Diesel - YQE 000010.

Therfore your information makes sense, the 2001 diesel is using YQE 000010.

Many thanks for helping me solve this one.

Pierre3.

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Has anybody knowledge or experience, what in the fuse box usually fails? Can it repaired … parts compatibility?
I know about burnt out blower relays from reading …

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https://web.archive.org/web/20180516002340/http://www.rangerovers.net/repairdetails/electrical/fusebox.html

Problem is usually weak spade terminals that the relays plug into, that creates a high resistance joint which leads to it heating up. Very early fuse boxes had a couple of tracks that were too thin for the amount of current they had to carry so would burn out too. By 98, after 2 modifications to the design, that problem was near enough cured.

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KCR - it does appear that new fuseboards/boxes are still available. I do suspect that the later fuseboards, - Petrol - YQE 103410; Diesel - YQE 000010 - may be used in place of the earlier boards - Petrol YQE103410; Diesel - YQE103420, if Richards view is correct. If the solder tracks on the board are lighter on the old board and the tracks on the new boards are heavier then surely they will fit.

I can understand why you wouldn't want to replace a later fuseboard with an early board, but I bet that there is no problem going from old to later boards.

Incidentally, here is a picture of the fusebox and board part numbers:
enter image description here

The details are written along the very bottom of the diagram.

Pierre3.

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Pierre3 wrote:

I do suspect that the later fuseboards, - Petrol - YQE 103410; Diesel - YQE 000010 - may be used in place of the earlier boards - Petrol YQE103410; Diesel - YQE103420

I very much doubt it as the loom part number changed at the same time as the fuseboard number changed so I suspect the pins on the underside are laid out differently. If you were to swap for the later board I suspect you'd need to change the loom too.

The 3 early part numbers were beefed up once they discovered weaknesses, hence going from a number for 94-97, then 97-98 and finally the 98 board which is backward compatible with the earlier ones. By the time the later ones were produced they had no doubt learnt from the earlier mistakes. On the petrol it makes sense for there to be a big change for the 99 model year onwards as that coincides with the change from GEMS to Thor so a completely different engine loom. Why there was a change to the diesel I have no idea, were there any major changes for the 99 model year diesel?

The fact the label is the same between the different fuels just shows that the fuses and relays are in the same place and do the same thing. One addition for MY 99 is the extra relay for the AC compressor clutch which the pre 99 cars didn't have.

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I guess it is something for a long evening and the several Electrical manuals on the screen in parallel for a comparison of the pin layouts?
I have a 98 V8 GEMS with the additional relay for the compressor clutch ... maybe it is possible to use one later (THOR) fuseboxes.
Maybe a comparison of the owner manual and fuse numbers will show differences, too.

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Again, thanks to Richard for a fairly detailed explanation. I suppose that to understand the whole issue would, as KCR says, mean getting all the model wiring diagrams and following each and every thread, to see if each fuse line does the same on all fuseboards.

I would agree with Richard that pictures of the fuseboards will indeed only show the location of the relays and fuses, and it should be fairly obvious, on reflection, that without studying the connections through the loom then using different boards just wouldn't work.

So I suppose the answer is - make sure a replacement fuseboard is the same part number as the one on the label in the fusebox lid ! I won't be the one to test the viability of swapping different boards !

Pierre3.

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Not necessarily the one on the lid, that may have been swapped at some point. Get the one that matches the VIN and fuel type.