1991 F250 4x4 wiring diagram or specifically, fusible links

[noddaz]

There are some fusible links next to the right side battery that connect to the solenoid on the fender. While servicing my truck today I noticed that one of these links is burnt. Tracing with my continuity tester I find that it is the large yellow wire that has it's link burnt. Can anyone tell me what this wire powers? I have been having some starting and charging issues for quite a while and can't help but think that this has something to do with the problem.
Thanks,
Scott

 

[TronDD]

What color fusible link? My diagram (which I don't 100% trust) shows a 20 gauge Blue fusible link to a yellow wire that powers a bunch of lights and an 18 gauge brown fusible link to a yellow wire that runs to the ignition.

Tim.

 

[noddaz]

color? of the link wire?

What color fusible link? My diagram (which I don't 100% trust) shows a 20 gauge Blue fusible link to a yellow wire that powers a bunch of lights and an 18 gauge brown fusible link to a yellow wire that runs to the ignition.

Tim.

Looks like the wire that branched off the big yellow wire was also yellow. The burnt link I cut out says "fuse link 20 ga fuse link 28 ga".

 

[TronDD]

So the fat yellow wire off the fender relay goes to fusible links and from there, there is a yellow wire for lights or a yellow wire for the ignition (according to the diagram). On my truck, I only have 2 links off the fat yellow wire, one is 18ga, the other is 20ga. The 20ga goes to another yellow wire so I am guessing that is ignition (the book says that goes through an 18ga link, though).

These wiring diagrams aren't great. They don't show wire gauge so I have to guess between all the wires of the same color.

Tim.

 

[noddaz]

Well, all righty then.
I made a section of wire to replace the burnt fusible link. Any idea what size fuse I should use if I make a inline ATC fuse for this?

 

[TronDD]

No idea what the formula is for X gauge fusible link to Y amp fuse. I'm no electrician.

I wouldn't leave it straight wire for long, though. The fuse link burned out for a reason. If that reason is still there, you could have a fire next time.

Tim.

 

[franklin2]

Go to the store and buy another fusible link and install it. They are small and compact, and make a neat job, and they work. This sounds like one of the main fusible links(there are several main yellow wires distributing power over there) and to replace a fusible link is going to require a maxi fuse. Most of the larger fusible links are going to require at least a 60 amp fuse to keep it from blowing. These fusible links are tough, and do nothing except save the truck from a catastrophic fire when some major happens. The only time they will ever blow is from a mechanic doing something wrong, poor aftermarket wiring, or a accident with the truck that damages the wiring.

 

[MontanaJack]

Thanks guys, I'll check them tomorrow. Like I said, I'm no wiring expert, so correct me if I'm wrong. Fusible links just look like really fat sections of wire because of their insulation right? Will I automatically know if they're burned up or do I just cut em all out and start new? And are they supposed to be pretty close to the relay solenoid behind the PS battery?

Thanks again, you're all a big help

 

[crash-harris]

I think you posted in the wrong thread

But if the links are burnt, they'll almost disintegrate when you touch them.

 

[MontanaJack]

I sure did
And thank you