Fusible link replacement

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Bryon
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Joined: Sat Dec 15, 2018 9:09 pm
Location: Raleigh, NC

Fusible link replacement

Post by Bryon »

I have been digging deep into a nest of horrible hack-wiring from an engine replacement my 89 GW went through. I have a couple fried fusable links connecting to the starter relay and I want to know if I should replace them with inline fuses. If so, which size wire/fuse, and if not, why?

It had several spliced wire segments and were not all the same gauge.

PossumJr
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Location: Eastern NC

Re: Fusible link replacement

Post by PossumJr »

Bryon wrote:I have been digging deep into a nest of horrible hack-wiring from an engine replacement my 89 GW went through. I have a couple fried fusable links connecting to the starter relay and I want to know if I should replace them with inline fuses. If so, which size wire/fuse, and if not, why?

It had several spliced wire segments and were not all the same gauge.
With fusible links you pick 4 awg sizes down from the wiring you are protecting. So if you have 10 awg from point A to B you would use a 14 awg fusible link in line with it. I won't really suggest which way to go as I don't have enough experience, but I would lean to staying with a fusible link as you would probably need to have a decent idea of variables like the max continuous current and the possible amount of surge that circuit would see to select a adequate replacement maxi-fuse or the like. Fusibles don't really work on an assigned current value and can easily take momentary surges of high current without issue, they are just there as a weak link for when shtf.
1979 J10, 360/QT
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Bryon
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Location: Raleigh, NC

Re: Fusible link replacement

Post by Bryon »

Thanks Possum!

The three fusible links connecting to the starter relay are all 14-gauge, right?
Any suggested brand? I saw individual links and I saw length of it to cut and circle connectors to make custom, any advantage or risks with this?
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tgreese
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Re: Fusible link replacement

Post by tgreese »

The link size is shown on the wiring diagram from the TSM here http://oljeep.com/gw/elec/89GW_elec/198 ... Switch.jpg

I've only used the ones in a kit from Bussman on Amazon. https://www.amazon.com/Bussmann-BP-FL-1 ... ref=sr_1_3
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Topic author
Bryon
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Joined: Sat Dec 15, 2018 9:09 pm
Location: Raleigh, NC

Re: Fusible link replacement

Post by Bryon »

Thank you for all of the information!
The one thing I wonder, is since I have an HEI distributor, would that keep a more co start energy flow? I do t want to use fusible links and get caught in the mountains with a burned one and have to replace a wire, when I could just have some spare fuses.
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tgreese
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Re: Fusible link replacement

Post by tgreese »

A fusible links protect the Jeep from fire in case of a catastrophe, like a wreck. Their job is to isolate the suddenly grounded circuit from the battery, and prevent a fire. They would not be casually replaced like a fuse. In service, they behave like a wire, so there's no issue with energy flow, whatever kind of ignition you have.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.

PossumJr
Posts: 103
Joined: Fri May 10, 2019 8:04 am
Location: Eastern NC

Re: Fusible link replacement

Post by PossumJr »

Bryon wrote:Thank you for all of the information!
The one thing I wonder, is since I have an HEI distributor, would that keep a more co start energy flow? I do t want to use fusible links and get caught in the mountains with a burned one and have to replace a wire, when I could just have some spare fuses.
tgreese already covered it, but to add; a properly sized fusible link in good condition has no reason to not hold up to the current it is expected to see, just like a fuse, and having an HEI distributor has no reason to change that. If you manage to burn up one, 9 times out of 10 it's because something is pretty wrong, more so than a blown fuse, and you need to start checking for shorts in your electrical system or a serious current draw that shouldn't be there.
1979 J10, 360/QT
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