Finding fusible link wire in the UK
Discussion
In a tight spot, I'm looking for 14 gauge fusible link wire (rust coloured GM wire). It's only available in America with corresponding huge delivery times and expensive shipping for little bits of wire...
Does anyone know where I can get fusible wire in the UK? Weeks of googling and I can't find the stuff anywhere...
Cheers!
Does anyone know where I can get fusible wire in the UK? Weeks of googling and I can't find the stuff anywhere...
Cheers!
Do you know what current rating and speed rating you need? Maybe you can find something suitable from domestic wiring suppliers. CUs with wire fuses are pretty rare these days but fuse wire is still readily available in a few standard sizes up to about 30A. Google turns up numerous fusible links designed for automotive use up to 100A or so.
You dont need to replace the fused link wire, you can use any high current rated fuses, some fuses can be found at http://www.littelfuse.com/products/fuses/automotiv...
Or http://uk.rs-online.com/web/c/fuses-sockets-circui...
There are plenty to be found at ebay
Buy fuse holders and fuses and extend the vehicle wiring to reach the new fuse holders
Or http://uk.rs-online.com/web/c/fuses-sockets-circui...
There are plenty to be found at ebay
Buy fuse holders and fuses and extend the vehicle wiring to reach the new fuse holders
I don't know the amp rating - there isn't really an amp rating for the wire as such. It's simply a last resort wire to prevent damage to the wiring loom. It's simply specified (in American terms) as 'four gauges smaller than the wire being protected' Therefore a 10GA wire needs a 14GA fusible link. There's no other speed or rating stipulated. I'm not sure domestic fuse wire is suitable as it doesn't come in the flameproof sheathe that a proper auto fusible link uses (happy to be corrected on that!).
I have contemplated the alternatives - but the location makes it a little tricky. The connections are onto the starter solenoid, in a very hostile environment beneath the exhaust manifold. I'm told the protecting link needs to be as close to the solenoid as possible, which is where the existing link is supposed to be. The midi holders are relatively large, and probably quite vulnerable in that location... so I ended up going back to trying to set the wiring loom to 'stock'.
One of the car's previous owners has bypassed one of the fusible links with an unfused wire directly from the battery, leaving the entire car wiring loom vulnerable. I hamfistedly broke a terminal on the starter solenoid, resulting in a short, some smoke and a dead car. I need to re-establish the links, simply so I can diagnose how much (if any) damage has been done to the rest of the loom...
I have contemplated the alternatives - but the location makes it a little tricky. The connections are onto the starter solenoid, in a very hostile environment beneath the exhaust manifold. I'm told the protecting link needs to be as close to the solenoid as possible, which is where the existing link is supposed to be. The midi holders are relatively large, and probably quite vulnerable in that location... so I ended up going back to trying to set the wiring loom to 'stock'.
One of the car's previous owners has bypassed one of the fusible links with an unfused wire directly from the battery, leaving the entire car wiring loom vulnerable. I hamfistedly broke a terminal on the starter solenoid, resulting in a short, some smoke and a dead car. I need to re-establish the links, simply so I can diagnose how much (if any) damage has been done to the rest of the loom...
I assume we're talking about some sort of car/truck.
It would help to know what that wire's rated to but if you don't know then 30A would be a reasonable guess for 10GA copper. Hopefully that's well above the current that circuit will ever see in normal use and it should be fused below that. At that sort of current I don't see any particular reason to use a fusible wire link instead of a conventional replaceable fuse.
Starter motor terminals tend to be a bit of a special case because they have exposed terminals often quite close to grounded metalwork but they also have high current connections to the battery - it's common for the main power connections to be protected by a high current fusible link or to be completely unprotected. There's no way that would use 10GA wire, though. The operating circuit for the starter motor solenoid uses much less current and might well be supplied by something in the 10GA range although that is a bit on the light side. This circuit would normally be protected by a fuse, just like any other circuit on the car.
It would help to know what that wire's rated to but if you don't know then 30A would be a reasonable guess for 10GA copper. Hopefully that's well above the current that circuit will ever see in normal use and it should be fused below that. At that sort of current I don't see any particular reason to use a fusible wire link instead of a conventional replaceable fuse.
Starter motor terminals tend to be a bit of a special case because they have exposed terminals often quite close to grounded metalwork but they also have high current connections to the battery - it's common for the main power connections to be protected by a high current fusible link or to be completely unprotected. There's no way that would use 10GA wire, though. The operating circuit for the starter motor solenoid uses much less current and might well be supplied by something in the 10GA range although that is a bit on the light side. This circuit would normally be protected by a fuse, just like any other circuit on the car.
Yes, the car's a mid-eighties Chevy V8 in a Camaro.
Power comes directly from the battery to the starter solenoid via an unfused wire, then two 10GA wires from the same pole (both with fusible links) supply power to the rest of the car.
My understanding is that fusible links behave differently from fuses and aren't necessarily interchangeable: a fuse will burn out when a current spike occurs, however a fusible link will resist current spikes that could result from being connected to several circuits. I believe midi fuses can replicate this behaviour.
It would be much easier if someone in the UK sold fusible wire so I could at least make up my own links! Of course in America you can just wander into your local Autozone and walk out clutching a handful for $5!
Power comes directly from the battery to the starter solenoid via an unfused wire, then two 10GA wires from the same pole (both with fusible links) supply power to the rest of the car.
My understanding is that fusible links behave differently from fuses and aren't necessarily interchangeable: a fuse will burn out when a current spike occurs, however a fusible link will resist current spikes that could result from being connected to several circuits. I believe midi fuses can replicate this behaviour.
It would be much easier if someone in the UK sold fusible wire so I could at least make up my own links! Of course in America you can just wander into your local Autozone and walk out clutching a handful for $5!
If originality isn't a big issue, then you can replace your fusible link with a maxi fuse,
This mopar forum link explains
http://minimopar.knizefamily.net/electrical-links....
This mopar forum link explains
http://minimopar.knizefamily.net/electrical-links....
OK I will try again.
You seem a touch concerned about something that is a simple fix
Let me 1st attempt to put your mind at rest about this minor problem
Many vehicles do not have any fused wire links or fuses in the power supplies from the engine bay to the interior of the vehicle, modern day vehicles do tend to have them
The fused links at the power supply pickup point which could be from the battery, starter motor or alternator are only fitted to protect the wiring loom from burning out if a supply wire shorted out in the engine bay or inside the vehicle, this is a "just in case what shouldnt happen does protection"
At present your power supplies are picked up from the starter motor, those supplies could just as easily be picked up from the battery terminal
There is no problem in carrying out a small modification, you could pull the wires out of the starter motor loom to an area where you can fit heavy duty fuse holders and fuses and even wire those back to the battery rather than the starter motor
Use Maxi Blade Fuse Holders And Fuses
Read the following link as it will help give you peace of mind
http://www.thirdgen.org/forums/electronics/336851-...
Dont use the small blade fuse holders like this person did, use the big ones
Which wire smoked at the starter motor
You seem a touch concerned about something that is a simple fix
Let me 1st attempt to put your mind at rest about this minor problem
Many vehicles do not have any fused wire links or fuses in the power supplies from the engine bay to the interior of the vehicle, modern day vehicles do tend to have them
The fused links at the power supply pickup point which could be from the battery, starter motor or alternator are only fitted to protect the wiring loom from burning out if a supply wire shorted out in the engine bay or inside the vehicle, this is a "just in case what shouldnt happen does protection"
At present your power supplies are picked up from the starter motor, those supplies could just as easily be picked up from the battery terminal
There is no problem in carrying out a small modification, you could pull the wires out of the starter motor loom to an area where you can fit heavy duty fuse holders and fuses and even wire those back to the battery rather than the starter motor
Use Maxi Blade Fuse Holders And Fuses
Read the following link as it will help give you peace of mind
http://www.thirdgen.org/forums/electronics/336851-...
Dont use the small blade fuse holders like this person did, use the big ones
Which wire smoked at the starter motor
Edited by Penelope Stopit on Tuesday 25th October 22:21
Edited by Penelope Stopit on Tuesday 25th October 22:22
Hmmm. That's probably a pretty good plan. Fusible links would be more straightforward as I can simply reproduce the stock wiring loom and carry on. However, I do already have a couple of new headlamp relays that I've installed ad-hoc in the engine bay (as stock the lights are switched directly through the dash!) so I could get a fuse/relay box and use it as an opportunity to tidy those up too into a combined relay/fuses junction box. At least the PO has already provided me with a power wire from the kill switch! I could just keep the power supply as existing to the solenoid, and then run the power connections to the rest of the loom directly from the new fusebox. At a guess, 30amp slow-blow fuses would probably do the job. Would a midi fuse be most suitable? When I google 'slow blow fuses' it comes up with those glass domestic-looking fuses.
I think the smoke actually came directly from the solenoid - when I took off the cap, you could see where the pole and contact inside had melted a little where they touched without being switched when the cap broke. Worryingly, there's no real evidence of a burnt wire down there... I really need to re-establish the connection so I can work out if the fusible link/by-pass have killed the car, or if there's some other horror buried in the wiring loom. There's continuity from the fuselinks into the car, and the under-dash wiring all appears sound. I really need the power back before I know where I am! Serves me right for working on the car when it's late and dark and I'm tired...
I think the smoke actually came directly from the solenoid - when I took off the cap, you could see where the pole and contact inside had melted a little where they touched without being switched when the cap broke. Worryingly, there's no real evidence of a burnt wire down there... I really need to re-establish the connection so I can work out if the fusible link/by-pass have killed the car, or if there's some other horror buried in the wiring loom. There's continuity from the fuselinks into the car, and the under-dash wiring all appears sound. I really need the power back before I know where I am! Serves me right for working on the car when it's late and dark and I'm tired...
Edited by NDNDNDND on Wednesday 26th October 14:02
I take it that you were working on or near the starter motor when the cap broke and smoked, if this is the case, it is not possible to damage any of the wiring harness with this type of short circuit, the battery lead will have been the lead carrying the excess current while the short was at the solenoid and the only lead that could have burnt out or melted a bit is that main heavy duty battery lead
Any big fuses will do the job, when you have completed your modification work it is advisable that you or someone else that has a good ammeter switches every electrical circuit on and checks the current consumption across the fuses, having checked the current consumption you will then be able to choose the correct amperage rated fuses
If it were me doing the modification I would measure the current being drawn at each fuse holder with everything switched on and then......(Here is a good page to read http://www.12voltplanet.co.uk/fuses-guide-uses.htm... example, If I measured 30 amps current draw across a fuse holder I would fit a 40 Amp fuse
Please note, in the above webpage current surges are mentioned, I haven't read the whole page as I don't need to, I have only posted that Webpage link to save me some typing (yes I'm a lazy ?) The thing is I don't know if it explains current surges so I will quickly explain and hopefully you will understand why circuits are fused at a higher rating than what current they carry during normal use
When switching most circuits on they will draw more current until up to normal working speed or temperature, wiper motors and fan motors are a good example, also when for instance it's snowing and you use a wiper motor to clear the screen that puts a really good load on the circuit yet the motor doesnt blow a fuse straight away, the fuse is rated to allow for the high current draw, this is just an example for me to explain it the easy way. In reality a wiper motor will often burn out rather than blow a fuse due to all the windings in it acting similar to a fuse and warming up until glowing hot and burning out
A starter motor will take a large ammount of current at start-up but that will decrease as it gets up to cranking speed
Headlights, fog lights and brake lights will all take a touch more current when first switched on
A nice big radiator cooling fan will take more current when it first kicks in
These are all surges that are not present once things are operating as they were designed to
This is why we fuse higher
I hope I haven't complicated things with the current surge explanation
Any big fuses will do the job, when you have completed your modification work it is advisable that you or someone else that has a good ammeter switches every electrical circuit on and checks the current consumption across the fuses, having checked the current consumption you will then be able to choose the correct amperage rated fuses
If it were me doing the modification I would measure the current being drawn at each fuse holder with everything switched on and then......(Here is a good page to read http://www.12voltplanet.co.uk/fuses-guide-uses.htm... example, If I measured 30 amps current draw across a fuse holder I would fit a 40 Amp fuse
Please note, in the above webpage current surges are mentioned, I haven't read the whole page as I don't need to, I have only posted that Webpage link to save me some typing (yes I'm a lazy ?) The thing is I don't know if it explains current surges so I will quickly explain and hopefully you will understand why circuits are fused at a higher rating than what current they carry during normal use
When switching most circuits on they will draw more current until up to normal working speed or temperature, wiper motors and fan motors are a good example, also when for instance it's snowing and you use a wiper motor to clear the screen that puts a really good load on the circuit yet the motor doesnt blow a fuse straight away, the fuse is rated to allow for the high current draw, this is just an example for me to explain it the easy way. In reality a wiper motor will often burn out rather than blow a fuse due to all the windings in it acting similar to a fuse and warming up until glowing hot and burning out
A starter motor will take a large ammount of current at start-up but that will decrease as it gets up to cranking speed
Headlights, fog lights and brake lights will all take a touch more current when first switched on
A nice big radiator cooling fan will take more current when it first kicks in
These are all surges that are not present once things are operating as they were designed to
This is why we fuse higher
I hope I haven't complicated things with the current surge explanation
Just had a thought
If you don't want to do a modification right now, you could buy a short length of fibreglass sleeving and then find some cable of the same size as the car loom cable that's connecting to the burnt out fusible links. Pull all the strands out of a length of short cable and throw 2 strands away so that you have 2 strands less than the loom wire, solder the strands to the loom wire and then cover with heatshrink, now cover the heatshrink with the fibreglass sleeving and then solder an eyelet terminal on the other end of the strands so that it will connect back up to the solenoid like the original fusible links
You have now made and fitted your own fusible link or links
If the original fusible links are not soldered but crimped it will be best to do the same, solder can melt with intense heat
If you don't want to do a modification right now, you could buy a short length of fibreglass sleeving and then find some cable of the same size as the car loom cable that's connecting to the burnt out fusible links. Pull all the strands out of a length of short cable and throw 2 strands away so that you have 2 strands less than the loom wire, solder the strands to the loom wire and then cover with heatshrink, now cover the heatshrink with the fibreglass sleeving and then solder an eyelet terminal on the other end of the strands so that it will connect back up to the solenoid like the original fusible links
You have now made and fitted your own fusible link or links
If the original fusible links are not soldered but crimped it will be best to do the same, solder can melt with intense heat
Edited by Penelope Stopit on Wednesday 26th October 17:46
The surge thing makes sense - I've seen something similar explained in the context of starter motors.
Thanks for all the info and ideas. Probably best is to hit a motor factors at the weekend and actually look at some stuff and see if I can form a plan.
Not sure I'm keen on the idea of stripping out a wire and cladding it in fibreglass - it's probably easier to obtain proper fuses than the fibreglass sheathe, and I think I'd prefer a properly rated wire!
Thanks for all the info and ideas. Probably best is to hit a motor factors at the weekend and actually look at some stuff and see if I can form a plan.
Not sure I'm keen on the idea of stripping out a wire and cladding it in fibreglass - it's probably easier to obtain proper fuses than the fibreglass sheathe, and I think I'd prefer a properly rated wire!
Land Rover used the wrapped fusible links for a short period in the Discovery & some RRC. Very quickly replaced with a fuse box & appropriate large fuses as in Penelope's posts.
They've proved problematic due to corrosion & many have been converted to the later fuse box. There was a repair kit & a Technical Bulletin by LR but AIUI the kit hasn't been available for some time. Not just on the V8, also on the 200TDi but replaced with the fusebox on the 300TDi
http://www.jpurnell.com/RR/repairs/fusible%20link%...
They've proved problematic due to corrosion & many have been converted to the later fuse box. There was a repair kit & a Technical Bulletin by LR but AIUI the kit hasn't been available for some time. Not just on the V8, also on the 200TDi but replaced with the fusebox on the 300TDi
http://www.jpurnell.com/RR/repairs/fusible%20link%...
Interesting link there: good to see I'm not the only one struggling to find replacement fusible links!
Interestingly that description also instructs you to solder the connections to the new fusible links, which tallies with what I have in my service manual. I think the 'no soldering' instruction relates more to resistance wire, which is another thing I've heard of but don't really understand!
Roll on the weekend...
Interestingly that description also instructs you to solder the connections to the new fusible links, which tallies with what I have in my service manual. I think the 'no soldering' instruction relates more to resistance wire, which is another thing I've heard of but don't really understand!
Roll on the weekend...
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