Melted wire and smoke

[Polardogg]

 

[ChildIdenticant]

I don't see anything out of ordinary regarding wiring. If you did put black to - and red to +, and the cables definitely have no short point then check your battery for the highly unlikely polarity reversal.
But looking at your previous post, your first "head scratcher", along with that toasted fuel pump relay suggest the underlying issue may have existed before you swapped batteries, possibly only becoming apparent with a healthy charged battery in the system. What other recent electrical work has been done that you know of?

 

[Polardogg]

I don't see anything out of ordinary regarding wiring. If you did put black to - and red to +, and the cables definitely have no short point then check your battery for the highly unlikely polarity reversal.
But looking at your previous post, your first "head scratcher", along with that toasted fuel pump relay suggest the underlying issue may have existed before you swapped batteries, possibly only becoming apparent with a healthy charged battery in the system. What other recent electrical work has been done that you know of?

My very first post on this forum was of an 98 this is a 94.
The only thing that i can make from this is the part of the boot is slightly charred ( the pic with my hand) that is the same wire that is attached to the alternator

 

[ChildIdenticant]

A Head Scratcher... is that not regarding this same 94?
Nothing that I see of the boot offers possible explanation for what has occurred.
That fuel pump relay is melted, correct?

 

[Polardogg]

A Head Scratcher... is that not regarding this same 94?
Nothing that I see of the boot offers possible explanation for what has occurred.
That fuel pump relay is melted, correct?

That was the 98 with fuel pump and i think that is the starter relay solenoid and the fuseable link from the alternator to it , melted

 

[ChildIdenticant]

 

[BKennedy]

I'm wondering if some wiring under that relay is creating a short. I have never seen a relay melt like that so its getting very hot. Pull the relay and check the plugs. The box can be pulled out of its mount with a few tabs on I think the fender side. Be careful, they break easily and take quite a bit of force a bad combination. There is just enough room to rotate the box and check the underside for burnt wiring.

I also would bet you cooked the starter relay. Its always good to have a spare anyway. Do you have a wiring diagram?

 

[CDW6212R]

Ditto, that melted relay is ruined for sure, and notice it is not a Ford relay, it has been replaced before? There is some damaged wiring somewhere besides that one fusible link, those melt when something else shorts out.

 

[Mbrooks420]

The relay is dated 2018 so it’s not that old. Time look at a wiring diagram and bust out a meter.

 

[BKennedy]

Starting to wonder if that melted relay in the power distribution box is the issue, causing a short. Here is the charging system diagram.

 

[Polardogg]

Starting to wonder if that melted relay in the power distribution box is the issue, causing a short. Here is the charging system diagram.
View attachment 327163

My electrical knowledge is limited

 

[Polardogg]

Starting to wonder if that melted relay in the power distribution box is the issue, causing a short. Here is the charging system diagram.
View attachment 327163

Could i take the relay out the 98 explorer and place in the 94

 

[BKennedy]

Borrow the relay for the AC

 

[Polardogg]

Borrow the relay for the AC

A/c is not hooked up in the 94 anyway

 

[ChildIdenticant]

Could i take the relay out the 98 explorer and place in the 94

Swapping relays is a quick fix when they fail normally. The melty is not normal, and suggests another issue. Check to see if the 20A fuse #18 blew .

 

[CDW6212R]

That bad relay looks good/promising on the terminal side. Maybe the relay took the main current damage, and the wiring underneath could be okay. The only good way to check is to flip the PDB over as suggested, carefully, and check the wiring and terminals going to that bad relay.

Those relays are the same as those of other Fords, 2001 is about when Ford changed relay shapes again. So yes you can any relay of the 98 you mentioned, being the same size as that bad one, and it work fine.

 

[Polardogg]

Swapping relays is a quick fix when they fail normally. The melty is not normal, and suggests another issue. Check to see if the 20A fuse #18 blew .

That bad relay looks good/promising on the terminal side. Maybe the relay took the main current damage, and the wiring underneath could be okay. The only good way to check is to flip the PDB over as suggested, carefully, and check the wiring and terminals going to that bad relay.

Those relays are the same as those of other Fords, 2001 is about when Ford changed relay shapes again. So yes you can any relay of the 98 you mentioned, being the same size as that bad one, and it work fine.

I tried to lift and take pic but it wont move there are 3 pics but they dont show much nothing looked fried i moved the ac relay and if i get the fuseable link replace think it run?

 

[BKennedy]

I don't know if any internet advice is going to help at this point. That relay cap is melted, but the internals look fine. Might have been subjected to a lot of heat when the alternator was hooked up wrong, which is what I have suspected all along. I would replace the fusible links, the relay, the starter solenoid, and any wires that the housing looks melted or loose and try again.

 

[ChildIdenticant]

To check for internal shorts on that power distribution box, opening it up is necessary.
20A fuse looks fine, so likely not switched fuel pump circuit.

Are you able to test the resistance/functionality of the "bad" relay ? If it still works, then it might be that it was just manufactured poorly, and the melted look has nothing to do with the fusible links blowing. Which , looking at the schematics, seems frustratingly possible. For something that would cause failure of this relay type to have also caused the fusible link to blow when the car is off, there would have to be something creating extra load on the relay coil side, and it would also need to be connecting to a wire that is hot , or the pcm relay has to be stuck closed.
think so anyway.

 

[Polardogg]

To check for internal shorts on that power distribution box, opening it up is necessary.
20A fuse looks fine, so likely not switched fuel pump circuit.

Are you able to test the resistance/functionality of the "bad" relay ? If it still works, then it might be that it was just manufactured poorly, and the melted look has nothing to do with the fusible links blowing. Which , looking at the schematics, seems frustratingly possible. For something that would cause failure of this relay type to have also caused the fusible link to blow when the car is off, there would have to be something creating extra load on the relay coil side, and it would also need to be connecting to a wire that is hot , or the pcm relay has to be stuck closed.
think so anyway.

What if the ignition switch was on? Its a little loose and may have been on?