mcc1979ian
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Posts posted by mcc1979ian
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2 hours ago, FridgeFreezer said:
That's better!
A 30A fuse for a 25A load is not unreasonable but you always want higher rated cable than the fuse - Bussman's data sheet has some good info, key point is a fuse will not be guaranteed to blow at 110% current, could take 2 minutes to blow at 135% of its rated current, and 5 seconds at 200% rated current! And that's if it's a good quality fuse not a random Chinese one. I'd be stepping up a wire size by default.
Generally you want the fuse as close to the battery end as practical, that way it's protecting the most stuff. Obviously there's practical limits to that.
Cheers, Iv run a main cable from battery to fuse box through a 150amp mega fuse. Would it be worth another main run to a fuse box near the switches to fuse the switch side of things too?
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Ok so Iv redrawn a plan for the led bar
300watt so 25amp fuse or would you step up to 30amp?
30amp cable from fuse to pin 30 or should I look at heavier cable?
11amp cable to pin 85 for earth
30amp cable from pin 87 to led or should I go heavier?
11amp from switch to pin 86
should I fuse before or after switch running a seperate supply from the fuse board running pin 30?
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56 minutes ago, FridgeFreezer said:
It depends a little how you want stuff to work but I'd say "yes".
The switch-to-coil side can be super low power, I have a single low-fused (<3A) permanent live and ignition-switched live that can be picked up for any switches I want to supply, they don't need their own fuse per switch.
The "high power" side (fuse to relay P30 to P87 to device being powered) you absolutely need the right size fuse for the load and wire that's rated ABOVE the rating of the fuse.
As I said, I tend to stop up a wire size if I get much above 50% of the wire's rated capacity as you not only need to allow for how slow fuses can be but also the voltage drop that you'll get down a skinnier wire as the load goes up - at 10A you're dropping about volt on a 5m run of 11A cable, which also means that cable is acting as a 10W heater.
Spot on, thankyou, I’m learning a lot from this post
Much Appreciated 🙏
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22 hours ago, FridgeFreezer said:
So:
Pins 85 + 86 are the relay coil and need bu&&er all power to operate, less than an amp. So wiring that part can use any old cable and might go something like: fused live feed --> switch --> Relay pin 85 --> Relay pin 86 --> GND
Pins 30 + 87 are the power side and carry the full device power, so both need appropriate wire size and the circuit needs to be fused correctly.
It sounds like you might've run 11amp cable from fuse to pin 30 which is not going to work if the circuit draws more than 10A / is fused above 10A.
Ah, think that could be my issue. Would I be better also running a seperate fuse for the supply to pin 30 from the fuse I run to the switch?
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Sorry meant fuse to pin 30 not 87🤦🏻
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9 hours ago, Maverik said:
Just looking at your photo and from what you've described, I'd say the wires you've used to the "powered" side of the relay is too small, so everything going to Pin 30 on the relays should be the same thickness as leaving the relay on Pin 87 - your photo looks like it shows thicker wiring leaving Pin 87.
What Amp rated wire have you used leaving Pin 87 going to your lights etc?
39amp to LED bar, think I used 25amp to front spots but I know Iv used 11amp from fuse to switch and back to relay pin 86 and same for fuse to pin 87
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6 hours ago, Maverik said:
It would be useful if you highlighted which wire you have a problem with on the original wiring diagram - I had a quick look through your old post but it wasn't so clear.
From what I understand, you've used 11amp rated wiring for the Relay switching system for your LED light bar?
To activate a 12v relay it only usually uses max 0.5amp to switch them so 11amp wire should be fine.
If this is the situation then you've got a problem.
Also these ultra bright LED's can pull some Amps - what light bar have you got
Ok on looking at your photo, have you fused the switch circuits as well as the relay supply circuits?
Sorry meant to say all my switching and 12v supplies to relay are 11 amp throughout. So same fuse used from fuse to switch and fuse to relay, plus 11amp from switch to relay
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Basically the led bar blows fuses, dash cam, attwood fan, volt gauge and small strobes but Iv a feeling whatever cable melted has took out the rest,
Hopefully this weekend I’ll pull the loom out and see for sure
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4 hours ago, FridgeFreezer said:
Looking back at your post on the light bar it suggests it's a 300W one, which would be 25A at 12v if the spec isn't massively lying like they all do... which would want 3mm2 in thinwall cable and ~4mm2 in regular. (calculator here)
I'd also ask if the cable is stuff sold by grown-ups or random copper-coloured aluminium junk sold on eBay from the far east... there's a lot of fake cable out there. There's also a lot of fake fuses...
If you've used 11A cable you should at absolute most be running a 10A fuse for the circuit, but given the way real-world fuses & cables behave, 7.5A would be about the max I'd be trusting it with. My general rule is >50% over-spec on the wire, so if something's drawing more than about 5A I'll step it up to the 1mm / 16A rated stuff.
I'll also mention that on my installs I've taken to fitting a MIDI fuse at the battery feed end, 50-100A are available, based on whatever the expected total load is going to be, that way if the big feeder cable should short on anything it is at least protected from making a small problem into a very big one.
Oh and next time buy a few different colours of wire, it makes life so much easier!
All the wiring came from an auto cable supply company. Buying large reels seemed an easy option at the time but thinking about it if I was to do it again I’d defo use a selection of colours
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6 hours ago, Maverik said:
It would be useful if you highlighted which wire you have a problem with on the original wiring diagram - I had a quick look through your old post but it wasn't so clear.
From what I understand, you've used 11amp rated wiring for the Relay switching system for your LED light bar?
To activate a 12v relay it only usually uses max 0.5amp to switch them so 11amp wire should be fine.
If this is the situation then you've got a problem.
Also these ultra bright LED's can pull some Amps - what light bar have you got
Ok on looking at your photo, have you fused the switch circuits as well as the relay supply circuits?
Hi, aye I fused both circuits, could that be my issue?
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Morning folks, hope everyone’s well,
a while back I posted about some wiring I was about to attempt, Iv got everything wired in but Iv melted a wire on my led bar, looking at my diagrams do we think Iv maybe gone too thin on cable. I used 11 amp cable from fuse to switch and back to relay plus from fuse to relay on most circuits. Panicked my baby was gona go up in flames when the smoke started but got the feed pulled straight away.
Iv numbered everything so that I know where all my cables go, just have a funny feeling Iv scrimped on cable. I’d attach this to my original post but for some reason I can’t find that one
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4 hours ago, FridgeFreezer said:
Reposing something Monkie posted ages ago:
Cheers, that’s handy to have. I wonder what they’ve been used for 🤔
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Afternoon chaps, Iv finally got my arse in gear and am getting on with the wiring in my 90. I’m currently up to fitting the raptor dash and it’s switches & gauges but Iv come across a plug where someone’s decided to install a couple of scotch type connectors but they ain’t plugged to anything.
My question is what is the purple and white wires their connected to for?
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Cheers gents, looks like once I get my arse in gear and get my workshop built I’m finally gona get my 85 v8 up and running 🤞
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On 9/2/2023 at 8:36 AM, Snagger said:
Please check my understanding:
You have two similar 90s. One has been a stalled project with new chassis, the other is now in need of work too. You want to use parts of the running vehicle, primarily body and dash parts and the rear axle, to continue the restoration of the earlier vehicle with its new chassis?
Assuming the new chassis complies with the regs by being of similar spec to the original (and having been new and unused), then merely swapping out an axle and engine brings you eleven points (chassis 5, steering 2, suspension 2 and transmission 2) and you only need 8. You will lose 2 points for not having both original axles and 1 point for the engine swap. Even if you decide to replace the transmission, you still have enough points for registration. Don’t worry about replacing dampers, bushes and springs (even changing their rates) - they are regarded as service replacements; as long as the design is the same, you are fine. What you can’t do while maintaining the points for the suspension is change to air springs, multi-link systems or start fitting modified arms like castor correcting welded radius arms.
Exactly that, to be fair most of the 85 has been used to keep the 86 going and the chassis is a brand new Richards like for like item
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Evening gents, Iv abit of a query regarding a chassis swap. Approx 15yr ago I started rebuilding a 1985 90, I bought a new galved Richards chassis not long after which I stamped with the vin number before painting. Since this I change suspension etc and swapped out the dead 200tdi for a 4.6v8 which Iv yet to fire up. Basically Iv not touched it for around 6-7yr but wanna get back to it.
The next part to the story is I bought a 1986 90 to use to run to work which I thought might give me a bit gee up to get on wi the 85, but I got carried away and spent the time on this, slowly robbing parts from the 85 to fit on the 86 like roof, doors, bonnet, x eng handbrake, disc rear axle and finally the bulkhead and some of the dash. Now my 86 could do wi a little tlc and a wee bit chassis work.
What I’m thinking is I’d buy a new rear tub as mines not great and the 85 one is a mess then strip the body off the 86, repaint and fit to the galv chassis I have stamped up for the 85 once I get the engine plumbed up and running.
My question is would it be legal to do this?
I still have log book, vin plate etc for the 85
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Spot on gents, thankyou
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Cheers, so ideally I’d be looking at my second and last link to get the engine and filter ends?
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So am I right in thinking sowt like these
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Evening chaps, I’m finally getting around to working on my V8 project again after a few year of life getting in the way, question tonight is earlier I was looking at the location of the oil filter (4.6v8 Gems) and I’m not too keen on where it sits and wonder if anyone knows of a decent oil filter relocation kit that would suit it? Also should I be running an oil cooler? I very rarely go off road with it and don’t push her overly hard
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On 10/26/2022 at 9:06 AM, FridgeFreezer said:
I'd suggest 40mm2 cable is not only overkill but is going to make your life hard - for charging a leisure battery you can probably safely stick with 16mm2 as it's never going to draw the full 110A out of your alternator, and it will be way easier to run & terminate.
I made a cable-size calculator tool a while back that will work out amps form watts & vice-versa plus appropriate cable sizes, fuse ratings, voltage drop per metre, etc.:
Now that could be very handy 👌
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Iv around 20 30amp switches with warning lights I bought a few year back and never used. That’s my only reason for the 30amp switches. I’m running a second alternator feeding a 110ah leisure battery which will lead to the fuse board through a 150amp breaker then distribute from there. Iv a pair of bud bars which I’m looking to run from the battery to then supply my earths. Iv got plenty 40mm battery cable which if I remember correctly handles over 200watt. I’ll most likely have one bus bar behind the raptor dash to handle earths for warning lights, cb etc
Wiring query
in Modified Vehicle Builds & Special Projects
Posted
Cool 🙏 Thankyou