Dave 001
Full Access Member
The wire (I think it's brown if I remember correctly) that goes from the large stud on the glow plug solenoid to the eight glow plugs is fusible link wire. (circled in red)
Fusible link wire is available in short repair sections as well as in rolls like this.....
Fusible links are more than just small gauge regular wire designed to burn out before the rest of the wire. Fusible link wire has very high temperature insulation which is supposed to contain (and keep insulating) the wire that is inside when in burns out from overload.
Fusible links do not always work as designed. I've seen fusible links were the insulation burned through before the wire burned out. But they do usually work. Even though fusible link wire is not perfect, International had a good idea to use it and I recommend you follow their lead.
Consider this..... all eight glow plugs draw about 120 amps total. You have (or should have) a 2 gauge cable feeding the glow plug solenoid from the batteries. With good, hot batteries you could have up to 2000 amps of wire frying, truck burning down power availabe. So for safety reasons you protect the glow plug circuit by installing a 150 amp mega-fuse between the battery and the 2 gauge cable. OK everything's cool now...but not really because a short in the glow plug circuit is most likely going to happen with the small brown wire. The 2 gauge cable (essentially starter cable) has very, very durable insulation (When was the last time you saw a starter cable short out and burn? I never have. That's pretty durable stuff. So durable none of the auto manufacturers even bother putting any type of short circuit protection on it. It's just connected right to the battery.) The brown wire is small, spends years sitting on top of a hot vibrating engine, sometimes has to deal with getting drenched in Diesel fuel, and the plugs that go on the glow plugs are well known for crumbling. OK, so the unfortunate day comes when the brown wire shorts out......it starts smoking, the conductor is glowing red (hmmm sounds a lot like a glow plug!!) and the Diesel fuel that's been leaking from o-rings (been meaning to fix that) starts smoking eventually lighting off and burning your beloved truck to the ground. But you have a mega-fuse...that can't happen. Not so. That mega-fuse was rated at 150 amps. 50 amps will easily fry that small brown wire and that 150 amp mega-fuse will feed a 50 amp short all day long. Sound far fetched? Not really. Electrical shorts have been known to cause vehicles to burn to the ground.
In a perfect world, each glow plug would have its own individual wire and each wire would have it's own 20 amp fuse. That would be excellent protection but it's not very realistic (especially for the OEM). So the next best thing would be to make the glow plug harmess out of fusible link wire and this is the route International took.
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Fusible link wire is available in short repair sections as well as in rolls like this.....
You must be registered for see images attach
Fusible links are more than just small gauge regular wire designed to burn out before the rest of the wire. Fusible link wire has very high temperature insulation which is supposed to contain (and keep insulating) the wire that is inside when in burns out from overload.
You must be registered for see images attach
Fusible links do not always work as designed. I've seen fusible links were the insulation burned through before the wire burned out. But they do usually work. Even though fusible link wire is not perfect, International had a good idea to use it and I recommend you follow their lead.
Consider this..... all eight glow plugs draw about 120 amps total. You have (or should have) a 2 gauge cable feeding the glow plug solenoid from the batteries. With good, hot batteries you could have up to 2000 amps of wire frying, truck burning down power availabe. So for safety reasons you protect the glow plug circuit by installing a 150 amp mega-fuse between the battery and the 2 gauge cable. OK everything's cool now...but not really because a short in the glow plug circuit is most likely going to happen with the small brown wire. The 2 gauge cable (essentially starter cable) has very, very durable insulation (When was the last time you saw a starter cable short out and burn? I never have. That's pretty durable stuff. So durable none of the auto manufacturers even bother putting any type of short circuit protection on it. It's just connected right to the battery.) The brown wire is small, spends years sitting on top of a hot vibrating engine, sometimes has to deal with getting drenched in Diesel fuel, and the plugs that go on the glow plugs are well known for crumbling. OK, so the unfortunate day comes when the brown wire shorts out......it starts smoking, the conductor is glowing red (hmmm sounds a lot like a glow plug!!) and the Diesel fuel that's been leaking from o-rings (been meaning to fix that) starts smoking eventually lighting off and burning your beloved truck to the ground. But you have a mega-fuse...that can't happen. Not so. That mega-fuse was rated at 150 amps. 50 amps will easily fry that small brown wire and that 150 amp mega-fuse will feed a 50 amp short all day long. Sound far fetched? Not really. Electrical shorts have been known to cause vehicles to burn to the ground.
In a perfect world, each glow plug would have its own individual wire and each wire would have it's own 20 amp fuse. That would be excellent protection but it's not very realistic (especially for the OEM). So the next best thing would be to make the glow plug harmess out of fusible link wire and this is the route International took.
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