Fusible link -- What Amp?

Dealing with all subsystems specific to the diesel powered Datsun-Nissan 720 pickup trucks.

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Zoltan
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Fusible link -- What Amp?

#1

Post by Zoltan »

My truck lacks the fusible link between the battery and the alternator. I found a nice pair of fused wires in a Honda that actually has real fuses (the glass type) in them. I am ready to splice in the new fusible link. What Amp fuses should I put in ?
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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asavage
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#2

Post by asavage »

Wow, good question. Based on the wire gauge, I'd guess 50A.

Thing is, fusible links are by their nature slow. The GPs will draw upward of 150A surge (for a second). While a fusible link handles that nicely, a typical fuse won't.

IOW, a Honda fuse replacement for the Nissan fusible link may not be a workable solution.
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.
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Zoltan
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#3

Post by Zoltan »

I am listening, Al. What gauge wire would be a good fusible link then?
- Zoltan -
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'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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asavage
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#4

Post by asavage »

I'm not sure, but I guess I'd cruise the MotorMite rack at my FLAPS for one that is just slightly smaller than 10 ga. Not very scientific.
redmondjp
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#5

Post by redmondjp »

Here's a web link with some reference information on sizing fusible links:

http://www.madelectrical.com/catalog/fusible-link.shtml

I don't know what the alternator's output is--assuming 40-50A, a 12GA fuse link should be fine.

One way to tell if a fuse link is sized properly--feel it. If so hot that you can't hold onto it (under normal electrical load conditions, and assuming the ambient temperature is not 150 degrees F), it's probably undersized.
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philip
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Re: Fusible link -- What Amp?

#6

Post by philip »

These fusible links are suppose to fail ... so, I have this 'hard'fix' handy in the glove box.

Image

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-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
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