Died while driving.

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My 92 3FE was blowing EFI relays and the problem ended up being the wire going into the fuse box where the relay plugs into was bad. It's underneath the fuse box under the hood. The wire gets brittle from the heat of the exhaust manifold and cracks at the connection. Need to replace the wire with a thicker gauge wire. It solved the problem for me.

Is it the wire from the EFI relay to the EFI fuse? In other wards, am I just replacing a wire from under the fuse box or am I redoing a wire from the efi relay to another location in the truck?
 
If your charge lamp (red light above voltmeter) did not illuminate WITH THE KEY IN THE ON POSITION then suspect:
fusible link AM2
ignition switch
7.5A IGN fuse (driver's left knee fuse panel)
7.5A CHARGE fuse (directly above EFI fuse in under hood fuse box)
If your charge lamp (red light above voltmeter) did not illuminate WITH THE KEY IN THE ON POSITION then suspect:
fusible link AM2
ignition switch
7.5A IGN fuse (driver's left knee fuse panel)
7.5A CHARGE fuse (directly above EFI fuse in under hood fuse box)

The only light that illuminates when I turn the key to the ON position is the open door light...nothing else. No CEL no CHARGE (battery light I am assuming), nothing.
 
If your charge lamp (red light above voltmeter) did not illuminate WITH THE KEY IN THE ON POSITION then suspect:
fusible link AM2
ignition switch
7.5A IGN fuse (driver's left knee fuse panel)
7.5A CHARGE fuse (directly above EFI fuse in under hood fuse box)

Opened the fuse box next to the steering wheel, missing ECU-B. Does this matter?

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Opened the fuse box next to the steering wheel, missing ECU-B. Does this matter?
Think about it. Did you pull that fuse and the engine stopped running, or was it running fine without that fuse?

It is unused.
 
Update: got the new fusible link in last night. Started right up. I let it run for a couple minutes to charge the battery. Then drove down my drive way and it died immediately. This time however, white smoke coming from the battery area? Looks like the black ground cable has a split thru it now (which is new). White smoke smells like burning plastic. Wtf? @jonheld what do you think?
 
Update: got the new fusible link in last night. Started right up. I let it run for a couple minutes to charge the battery. Then drove down my drive way and it died immediately. This time however, white smoke coming from the battery area? Looks like the black ground cable has a split thru it now (which is new). White smoke smells like burning plastic. Wtf? @jonheld what do you think?

Awe man that sucks. I was so happy to read it was the links and saw the dreaded follow up post soon after. Subscribed. Did the new links melt?
 
Update: got the new fusible link in last night. Started right up. I let it run for a couple minutes to charge the battery. Then drove down my drive way and it died immediately. This time however, white smoke coming from the battery area? Looks like the black ground cable has a split thru it now (which is new). White smoke smells like burning plastic. Wtf? @jonheld what do you think?
Follow the smoke? Hard to diagnose from a distance, but you have a short somewhere.
What fusible link opened? That will help narrow it down.
Was it AM2 again?
 
C'mon now. You're not keeping up with the rest of the class.
Post #56 in this thread.
Is there supposed to be a certain way the fusible link is hooked up to the positive terminal on the battery? I noticed there are two contact points on the link that attach around the head of the positive terminal. Is that main wire supposed to be in between the two? Or does it not matter? Below I will post pictures of what I mean. Also I will post the new fusible link that just burnt up in the positive terminal.

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F1FF0A26-E64D-4317-BBFE-68BD8850079A.webp


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86F46E07-FAF9-4C14-94CE-5A86DB60ACDF.webp
 
Just placed the new fusible link(my back up to the back up) in and have all correct lights back up on the dash with the key in the ON position. After the first one burnt up. I was back at square one. However, now I’m nervous to restart it. Negative terminal lead smells like burnt plastic. Also, now have +12v from the B+ terminal. Checked the pins in the EFI relay with the multimeter. All good. Just don’t want to burn up my second fusible link. Making sure the set up is correct before firing. Thanks.
 
Could this all be a grounding issue? I checked the nut off the chassis for the negative lead. Was a little loose so I tightened that. The lead going to the engine has +12v at that connection point. Positive terminal WAS a little loose upon inspection, could that have anything to do with it? Notice the burnt up fusible link in the previous pictures. I’m sure there is a short somewhere. Just not sure where. Had to put electrical tape over the negative lead from where it was rubbed. Notice where the wire runs from the battery thru that hole. That spot was rubbed off and wires were exposed. So I covered that up. This is where I believe the plastic burning smell was coming from.
 
Couple of thoughts here.
1. The "burnt" part of the terminals on the fusible link was caused by arcing. That was caused by a poor connection and was the likely source of the smoke and smell.
2. I don't recall ever seeing battery terminals that looked that bad. They are corroded and makng poor contact. And who has been chewing on them? Throw those in the garbage please.
McMaster-Carr
3. It makes no difference if you separate the fusible link terminals. The electrons don't care. I wouldn't do that, but it makes no difference. The key is to have a good solid connection point. Any poor connection will cause arcing.
 
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