6.0 glow plug harness-- no fusible link?

[The_Josh_Bear]

So I ordered a CDD GP harness and after a week or so he canceled the order. Dunno why, no reason given.

So I ordered a 6.0 harness cause they are dirt cheap but it doesn't seem to be made with any fusible link. Should it be? Turns out it's a hard thing to Google.

Assuming it's not, how would we fuse this setup ideally? I feel like a bunch of people are running a 6.0 harness and it might be a fire waiting to happen. Or at least a problem area.

 

[hacked89]

You fuse the hot feed to a relay closest to the battery you can. Then fuse any other hot sides of relays that may be off that relay. You can see mine here with the primary fuse behind the coolant bottle.

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[hacked89]

Most of your truck is powered off of the hot side of the starter relay which ford doesn't fuse from the factory but I switch most things over to a break out box and fuse the GP relay you see in the pic, and every other accessory. Including the alternator back to the battery.

 

[The_Josh_Bear]

You fuse the hot feed to a relay closest to the battery you can. Then fuse any other hot sides of relays that may be off that relay. You can see mine here with the primary fuse behind the coolant bottle.

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I like your spot for the White Rogers relay. My passenger side is getting crowded so I'll likely aim for that spot myself.
I also added a big fuse for my 3G alternator upgrade.

 

[hacked89]

Heads up if you do it exactly how I did you have to clearance the hood

 

[The_Josh_Bear]

I still have my cruise control there so it could be decision time as yours is gone. I prolly haven't used it twice in 10 years.

 

[franklin2]

Fuses are large and bulky, and their connections are susceptible to corrosion. All things that can be overcome, but one of the many reasons the factory used and still uses fusible links to this day. A fusible link is simply a undersized piece of wire with special insulation around it that will not catch fire when the wire melts.

 

[Nero]

Just as an FYI, CDD is out of stock, probably why the order got canceled.

 

[ROCK HARVEY]

If you are keeping the stock glow plug controller, aren’t there fusable links on the two 10ga wires that feed power from the passenger fender to the GP controller? I have the 6.0 glow plug harness, but I kept the stock controller and everything else.

 

[The_Josh_Bear]

Fuses are large and bulky, and their connections are susceptible to corrosion. All things that can be overcome, but one of the many reasons the factory used and still uses fusible links to this day. A fusible link is simply a undersized piece of wire with special insulation around it that will not catch fire when the wire melts.

So everything I've read agrees with this-- but I literally just tore apart my harness and it has zero fuse link in it. It's all at least 12ga wire and good portions aren't even insulated! I'll get a picture. Imagine my surprise when I find wires running straight to the GP's with no insulation at all, wrapped in loom with 6 other wires.

So I guess the fuse link for an 89 is somewhere else? I'm about to go investigate. I'm guessing behind the battery where a whole pack of fuse links run.

Pics:

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There is no writing on the insulation for size or type or anything that I could find. I'm considering clipping the ends off and running this harness again since it's so beasty and still clean. The POS 6.0 harness is 14-16ga and that's no exaggeration.

 

[The_Josh_Bear]

@hacked89 what amp rating for the fuse? I was thinking 300 since I know it's 220+ amps before I got the bigger relay.

 

[hacked89]

@hacked89 what amp rating for the fuse? I was thinking 300 since I know it's 220+ amps before I got the bigger relay.

250

 

[franklin2]

So everything I've read agrees with this-- but I literally just tore apart my harness and it has zero fuse link in it. It's all at least 12ga wire and good portions aren't even insulated! I'll get a picture. Imagine my surprise when I find wires running straight to the GP's with no insulation at all, wrapped in loom with 6 other wires.

So I guess the fuse link for an 89 is somewhere else? I'm about to go investigate. I'm guessing behind the battery where a whole pack of fuse links run.

Pics:

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

There is no writing on the insulation for size or type or anything that I could find. I'm considering clipping the ends off and running this harness again since it's so beasty and still clean. The POS 6.0 harness is 14-16ga and that's no exaggeration.

That piece in the picture is a splice. Like the other poster said, the original harness had two 10 gauge wires and each one had fusible link right at the solenoid on the fender. Like fuses, fusible links are installed as close to the beginning of the circuit as possible, to protect as much of the wire as possible. If you have a problem behind the fusible link, then it would not work to protect the wire.

 

[franklin2]

Here's the diagram for your 89 original wiring. If you look in the upper right corner, you can see where all the fusible links are located, right at the starter relay on the fender. The diagram doesn't show the actual links, but makes a reference to where they are located. The diagram shows the two glowplug feed wires as "black/orange" and you will find those same two at the bottom of the diagram feeding the glowplug controller. But as we all know, these wires are usually yellow also.

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89 truck wiring 1 by D Franklin, on Flickr

 

[hacked89]

Fusible links are 1. Cheap 2. Save space, mostly cheap is why a company will still use them. 80s ford wiring was not the epitome of electrical engineering. That black with orange wire also runs directly to the headlight switch hot at all times. No relay to headlights. And the switches dimmer function is a fire risk as it wears out. As examples. I generally agree that a rule of thumb of the OEM design is better than backyard designs but not always when you factory in $$, space, and comfort, because they have to cater to the average consume.