Is the main fuseible link wire made up of standard wire? ( It protects from overload fires )

[Bob Dunahugh]

I had the original neutral safety switch stop working at a camp ground. I picked up a new one . Was made in China. Tried it a couple of times after installing it. Perfect.Two days later we went to leave. Turned the key. No action. Except for all the smoke coming from the right front. The new switch from China shorted out internally. Thank you fusible for saving our GMC. Bought a GM switch. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, January 6, 2019 6:00 PM
To: gmclist
Subject: Is the main fusible link wire made up of standard wire? ( It protects from overlosd fires )

But it burns. ( GRIN.) Sure was a SHOCK when ours burned. I know that the insulation is different in someway. So is the wire material different then standard copper wire? For those that don't know what/were it is. From what I think I know. ALL 12 volt power for the vehicle. All lights including head lights ,starter solenoid, ( heater blower motor except high, A/C compressor, radio, and your ride height compressors. NOTE. Not the house 12 volt system. } Has to be delivered from the battery by way of this 16 gauge wire. A fusible link. In this system. Is to be two wire gauge sizes smaller then the largest wire in the system. As 10 gauge wire is our largest. Battery cables aren't included here. The link is about 6 inches long. And goes from the main 12 volt terminal. To a large terminal on the bottom of the horn relay. So. Is that wire just copper? Bob Dunahugh 78 Royale

 

[Ken H.]

Bob,

As others have replied, there's nothing special about the fusible link
WIRE. But the insulation IS special. You should be able buy "fusible link
wire" in the proper gauge, by the foot, at 'most any parts store (except
perhaps the chains).

Ken H.

> I had the original neutral safety switch stop working at a camp ground.
> I picked up a new one . Was made in China. Tried it a couple of times
> after installing it. Perfect.Two days later we went to leave. Turned the
> key. No action. Except for all the smoke coming from the right front. The
> new switch from China shorted out internally. Thank you fusible for saving
> our GMC. Bought a GM switch. Bob Dunahugh
>
> ________________________________
> From: Bob Dunahugh
> Sent: Sunday, January 6, 2019 6:00 PM
> To: gmclist
> Subject: Is the main fusible link wire made up of standard wire? ( It
> protects from overlosd fires )
>
> But it burns. ( GRIN.) Sure was a SHOCK when ours burned. I know that the
> insulation is different in someway. So is the wire material different then
> standard copper wire? For those that don't know what/were it is. From
> what I think I know. ALL 12 volt power for the vehicle. All lights
> including head lights ,starter solenoid, ( heater blower motor except
> high, A/C compressor, radio, and your ride height compressors. NOTE. Not
> the house 12 volt system. } Has to be delivered from the battery by way of
> this 16 gauge wire. A fusible link. In this system. Is to be two wire
> gauge sizes smaller then the largest wire in the system. As 10 gauge wire
> is our largest. Battery cables aren't included here. The link is about 6
> inches long. And goes from the main 12 volt terminal. To a large terminal
> on the bottom of the horn relay. So. Is that wire just copper? Bob
> Dunahugh 78 Royale
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> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[Tom Newell]

So my IH Scout recently had a failed fusible link due to ham fisted ammeter removal by "someone". Anyway, it did not fail at the time of the ham
fistedness, but rather later in a Home Depot parking lot (a rather decent place for this sort of problem on a 45 year old vehicle.) To the ideas
raised earlier about corrosion (and or degradation due to time), it did not fail in the length of the wire, but rather at the connection point for the
bullet connector, with this particular bullet connector appearing to be designed specifically to have a "fuse" effect of its own (speculation).

International used a Delco starter with the same poorly thought out wiring scheme as GM, with a bunch of fiddly wires (and a fusible link) way down at
the bottom of a notoriously leaky engine and bewilderingly close to the exhaust manifold (my Ford pickup is so much better with all this stuff safely
up on the inner fender at the solenoid). Additionally, Scouts have a poorly designed and dangerous wire setup in general, and time has not improved
this circumstance. And guess how easy it is to figure out the specifications of an old International fusible link.

The convergence of circumstances forced me to complete rather a lot of research on fusible links and the construction of same. There are very forceful
and official sources stating that the fusible links should be:
1. absolutely not soldered
2. absolutely soldered
3. about 8.5 inches long
4. exactly the same length as the old one
5. etc., etc...

So to avoid continuing to beat myself about the head and shoulders, it was time to find an actual modern solution. Initially much more gibberish,
until I finally found this:

https://www.littelfuse.com/products/fuses/automotive-passenger-car/high-current-fuses/298.aspx

These are specifically specified as a "slow blow" fuse for battery and alternator protection, and snazzy mounts are available for retrofit
applications. Also, this page has links to pages and pages of information that seem to teach everything that needs to be known about automotive fuses.
So I was on the right track.

Then over Christmas, I installed an AMP Research Power Step (highly recommended, though many $) on my Dad's brand spanking new 2019 GMC 2500. During
the course of this installation, I became aware of how modern (or current, if you prefer) GM engineers handle fusible linkage. What they do is have
very short positive battery cable (4 or 6 inches maybe) that goes a bus that clips to the top of the battery. This bus cleverly and conveniently
includes a snazzy jump-start point, and also (apropos to this discussion) a series of fused connections branded as "Littelfuse" and identical in
construction appearance to the "Mega fuse" items covered in the above link. There are two 60 amp connections of the connection plug variety, and
several stud connections ranging from (I think) 100 amp up to 400 amp (!). The starter is on the 250 amp stud (I think); the 400 amp is open (winch or
plow, maybe; this truck does have the snow plow package). Conveniently, I was able to use an open 125 amp stud to feed to power step items (there is
an inline 30 amp fuse in that harness; I certainly do not want 125 amps blasting through that equipment.)

So my take-away is that, if I possibly can, I am going to track down one of the battery top bus thingys to retrofit to all my old stuff (if it is at
all possible/practical). If the thingy is not a reasonable retrofit, I am going to get the Mega fuses and make my own setup.

And having said all that, I currently have an old fusible link of somewhat questionable providence down on the starter of my Scout. So it goes...

Tom Newell
San Pedro, California

 

[Bob Dunahugh]

O Riley's has a 6 inch fusible link that fits our 78 GMC. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Monday, January 7, 2019 9:44 AM
To: gmclist
Subject: RE: Is the main fuseible link wire made up of standard wire? ( It protects from overload fires )

I had the original neutral safety switch stop working at a camp ground. I picked up a new one . Was made in China. Tried it a couple of times after installing it. Perfect.Two days later we went to leave. Turned the key. No action. Except for all the smoke coming from the right front. The new switch from China shorted out internally. Thank you fusible for saving our GMC. Bought a GM switch. Bob Dunahugh

________________________________
From: Bob Dunahugh
Sent: Sunday, January 6, 2019 6:00 PM
To: gmclist
Subject: Is the main fusible link wire made up of standard wire? ( It protects from overlosd fires )

But it burns. ( GRIN.) Sure was a SHOCK when ours burned. I know that the insulation is different in someway. So is the wire material different then standard copper wire? For those that don't know what/were it is. From what I think I know. ALL 12 volt power for the vehicle. All lights including head lights ,starter solenoid, ( heater blower motor except high, A/C compressor, radio, and your ride height compressors. NOTE. Not the house 12 volt system. } Has to be delivered from the battery by way of this 16 gauge wire. A fusible link. In this system. Is to be two wire gauge sizes smaller then the largest wire in the system. As 10 gauge wire is our largest. Battery cables aren't included here. The link is about 6 inches long. And goes from the main 12 volt terminal. To a large terminal on the bottom of the horn relay. So. Is that wire just copper? Bob Dunahugh 78 Royale