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1995-2002 Range Rover P38A
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I've spent some time before posting, done my homework first, looking through other conversations about the fuse box and what appears to be a typical overheating problem at the RL7 relay. I'm seeing a couple of different responses, so I want to make sure I have the latest advice before tinkering. I am a novice mechanic and usually outsource repairs, but I'm also handy, have some tools, and can do stuff so long as I know how to do it. But diagnostics aren't my thing, so I usually don't know how to do what needs to be done. I recently acquired a 1999 P38 in pretty good shape. Just under 109,000. Driven it about 500 miles so far with no problems. Love it. During that time I've watched all the P38 vids on YouTube, read a bunch of threads on this site, and gotten myself a copy of the RAVE workshop manual. So I was poking around and opened up the fuse box the other day to find brown discoloration on the RL7 relay. It needs to be addressed. Some say to replace RL7 with a 40amp relay. If so, where does a guy get one? Again, I'm not well versed in parts or parts acquisition. It's also hard to tell where I can buy RR parts online, so any advice there is appreciated. I'm on U.S. mainland. Happy to order parts from the right place.Others say the problem isn't the relay, but the electrical path prior to the relay. This is where all the soldering and rewiring suggestions happen. I've read over this page, too: https://www.rangerovers.net/repairdetails/electrical/fusebox.html#socketSo, what should I do first? Yank out the relay and look for a replacement? Or should I bust out the soldering kit and get to work? If so, I'll still need to replace the almost-fried relay. Where do I get replacements?Many thanks in advance to those offering suggestions — or just direct me to the thread. Glad this forum is here.
 

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1995-2002 Range Rover Classic
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in no particular order or preference, atlantic british, rovers north, land rover direct, p38 spares, paddock spares, bearmac, just a few some in the us some in England.
 

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1995-2002 Range Rover P38A
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Discussion Starter #3
Thanks for the references. Already finding what I need at Atlantic British. // In the fusebox, relays 2, 10, and 19 correspond on the diagram (on the inside of the fusebox cover) to an icon showing an engine with an arrow running through it. What does that icon represent?
 

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1995-2002 Range Rover P38A
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Welcome.Well, he was my permanent fix; all is still well and good.Most owners just replace the fuse box with a new one. some have reported a repeat problem in short order, others we simply do not know. All I know is that area of the fuse box was under designed for the load it carries and fails quite often. I'm guessing your fan doesn't go to high, but you will not know what high is till you fix this. Best of kuck https://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/225890-new-fuse-box-external-relocation-rl7-relay.html
 

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Be sure to take a good look at the area on the board where the relay plugs in. It may be well burnt by this time........
If so, and you are still feeling handy, use David's neat method, be sure to get the very best quality
quick connects you can (Anchor Marine make very nice ones) I would use stranded wire instead of the solid he used. It is less prone to vibration, bends easier, and crimp on lugs are designed for stranded wire anyway.....
If the connections on the board have been burnt, the terminals will not make a good connection to your new terminals, so you will need to remove, and disassemble the fuse box, and solder your wires to the board rather than plugging them in. Just make the hole in the inside base where the relay used to sit bigger to lead your new wires out of. (again, stranded wire will help here)
Of course, if the fuse box base is in good shape, you could just put in a new relay and run it for another 100k miles?
 

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Discussion Starter #6
Yes, the fan has been a bit sporadic, so I ordered a new relay and will see how long that lasts. If I end up needing to get a new fusebox, I'm going to try to beef up the connections before installing it. But if a new relay will go for another 100K, it will be years before I put that many miles on it. // Question: what happens if you just take one of the relays out (RL7) and drive it around that way? Just a fan that won't work, or something worse? — Thanks guys.
 

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1995-2002 Range Rover P38A
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If i'm not mistaken (Looking at RAVE), RL7 would be for your HEVAC fans, cigar lighter, and radio? If you plan to keep it around a long time, I would just suggest to just open it up and spend some time in there re-working some of the solder joints. Did that to mine and am definitely glad I did. Look at some of these cracked cold solder joints I had. I also beefed up the RL7 power wire by adding a heavy gauge stranded wire in to the mix as well. Plus, after it was all said and done, my fans came back to full strength!

20180217_142432.jpg 20180217_142437.jpg 20180217_204842.jpg 20180217_210607.jpg

Edit: Are image attachments having issues?
 

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Discussion Starter #9

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1995-2002 Range Rover P38A
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4th Picture is just showing what a lot of the solder joints looked like before repair. Yup, that's the page to use. It really isnt' hard to do, just a little time consuming, but well worth it.
 

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I would highly highly highly recommend replacing your fuse box with a brand new one. I would also replace most of the the relays. I bought a new fuse box and 17 relays from LR Direct and got it all delivered for about $260.00. If one relay is brown there are others that will be just as old and in need of replacement. Save yourself over 40 hours of guessing and trouble shooting all while fighting electrical gremlins. It was the best peace of mind job yet.
 

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Discussion Starter #12
Yes, I've been thinking about that. But won't the exact same pattern of burnout and cracking happen on the new fuse box?

It's probably hard to say how many miles a new one will last before that happens, but mine appears to be the original, and if it took 108K to get to this point, then depending on how much A/C and heater I use, a new fuse box could conceivably get me to 200K.

Thanks for the advice.
 

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1995-2002 Range Rover P38A
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One of the big reasons they overheat and give problems is because over the years there's additional load placed on the circuit. Both of the relays in that bottom/right corner are for the blower motors. They power nothing else (the other RL7 that does the HEVAC power is in the BECM).

There have been various theories about why the end up drawing more current and failing, from the pollen filters being blocked, to the brushed wearing down etc. Whilst they probably have an impact to some degree, the biggest reason I've found is in the RHF footwell, behind the kick panel are a few connectors which are known to get water in and corrode - it's well documented with various P38 issues.

One of the connectors in there is a but 2 way connector with a couple of beefy wires in them... they are the main +ve feeds from the fuse box and the relays that fail, to the blower motors. On my P38, I haven't had the issue with the crispy relays luckily, but even though the connector looked OK, there was still signs of corrosion. When I cut the connector out to solder/heatshrink the wires together, I found signs of corrosion internally in those wires, and ended up not being able to get solder to take, so crimped them together after cleaning off as much corrosion as possible.

Corrosion causes resistance in the wire, which causes heat - and also causes more current to be drawn, which I believe is one of the contributing factors to the fuse box/relay failure.

I would at least check the condition of these wires in that area whether you replace the fusebox or not.
 

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Spot on Marty NZ. Absolutely check out those connections. I would expect a new fuse box to go at least 3 to 4 years or 60k miles. It is an expendable part in my mind. All of the plastics on p38’s “dry out” and become brittle and crack or break. A LOT of my truck is held together with 2 part plastic specific epoxy. The chemical engineering at the time of production was not the best.
 

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Thanks for the tip on that connector, Marty.
I had been speculating about increased current draw over time as well, and that would certainly explain some of it. I would also add that the contact resistance of almost any relay will increase with use simply due to normal erosion of the contacts.
Add a bit of moisture, and this effect will be accelerated until the relay literally burns up.
Taking the base out with it!
As for longevity? A new one should last about as long as the old one did.......10-20 years?
Since we are now aware of the issues, we can also keep an eye on the relays and replace them at the first sign of overheating.

There have been great high temp-high impact plastics available since the early 60's.
In the case of this fuse box, I would speculate that they just went cheap, just like the other plastics in the P-38 that shatter when you give them a casual glance! (Don't even mention the headliner!)
Incidentally, the "haze" that accumulates on the inside of your windscreen is actually
caused by the plasticizers that are indeed evaporating from all the plastics inside the cabin.
It is a real shame that they only looked for 10 years service life on the trim when the basic truck should last 50!
 

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Martnz knows!...whatever he says...clipping tthe connectors off and direct-soldering the RH footwell pair of thicker wires is the best solution to to this 20-yr old discussion about the source of high resistance in this blower-fan circuit...the resistance is within the wire-to-connector, not just connector-to-connector. I once had 2 years of grief with the same issue in a batttery cable-to-terminal connection.
I have just spent time in side my clipped-open fusebox looking for any issues...this was a newish box, after the RL 7 socket area charred black on my original, and had not many hours of use. Firstly, I recommend using a Dremel fine cutting disc to neatly separate the board end-pins...it makes rejoining them a lot easier than making and replacing new pins...'RSW fusebox repair youtube' shows how to reconnect by solder-flowing the cut ends, and avoiding 2+ hours of messy work, and possible track damage.
The pcb copper traces are thick, but are insulated with epoxy, which inhibits heat dissipation from the tracks. Both RL6 and 7 feed Aqq/C blowers, but 6 is less affected by burning, because its tracks are longer on the board (due to layout concerns), allowing more heat dispersal. RL12, the fuel pump relay, also scorches because it is constantly on, and it's track to the board edge-pin is very short, preventing heat dissipation. I scraped (with a flat-blade screwdriver) the epoxy coating off any tracks that were discoloured by heat and flowed solder thickly along them, to provide a lower-resistance path and a greater surface area for heat dispersal. I also re-flowed the pad where the main Battery cable enters, and those where the 3 output posts that feed the BECM leave. Check every solder joint on the board for hairline dry-joint cracks. I also reflowed the track along the edge that supplies the maxi-fuses, and siamesed any pins that entered a common pad. The purpose is to permanently correct original short-comings; no point in replacing a board with a new one that will inevitably give you the same problems again.
I used a Dremel micro-disc and arbor in my standard drill to minimise the gap between the pins to be rejoined; I also used a Dremel wire brush disc to polish the scraped tracks before soldering-flooding. Thoroughly flush (with board-cleaner spray) the resulting copper dust off the boards before rejoining
I removed the excess varnish between the copper bands joining the two pcb boards to improve air flow, and cut away part of the separating black plastic dividing wafer covering the RL6 and 7 tracks for the same reason.
Stand the boards on edge when rejoining, so the pin-halves dont drop out...keep tweezers handy to hold them.
This should be a permanent fix.
 
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