I have lost all juice it seems to bronco. was searching around found a wire by the starter relay seems to have melted off the right side of the relay. Not sure when I touch it to right side of relay it turns truck over and wire glows red. The bronco was runnin great down the road then nothin . pulled her over had her towed and got this far hate to be starting changing parts till I ask.btw its a 84 2.9L

 

same thing happened to me... still havent found the exact problem yet. But i had autozone do the battery and alternator test when it happened and my battery was totally gone. So for a little over $100 i got a huge 850 cold crankin amp battery and i havent lost all power yet. They also said my alternator was going out. Seems fine to me so far, it still puts out enuf juice for all my 9 KC daylighters.. (check out the pics @ http://www.cardomain.com/memberpage/625828 ) But then sometimes, even when im not running any lights, my power will fluctuate and go way down. My gauge sits at about 15 (middle of gauge) most of the time.. but when it does move it goes close to 12 (almost off the gauge). Now another thing is that i had all kinds of problems with my electical system lately.. all my guages would jump for a split second and sometimes i would have no juice at all. Replaced both battery cables and that part went away. But the gauges would still jump around. Put in new computer and that part is solved. Now i just have the problem where my amp gauge goes really low for no reason at all, and i know its not just the gauge being goofy cuz my headlights dim when it does it. So enuf of the story, heres what you do:
1. check both battery cables, if theyre even the least bit coroded or anything, replace em.. theyre cheap. Oh ya and make sure you check the cable going from the starter relay to the starter.. you said it would crank and glow so i think you have a problem there. And double check your engine size, they didnt make the 2.9 in '84, so it's either the 2.8 or it has been swapped.. but its a good thing to know.
2. get your battery and alternator checked.
3. check the diagnostic codes.. see if your computer can help you, that is, if you can get juice to it.
4. and last of all, definately, definately check to see if youre grounding out anywhere.. that messes up all kinds of stuff. (my horn, cruise control, and brake lights all dont work right now and im pretty sure its either a bad ground or a ground where it shouldnt be grounding) Well sorry this was soooo long.. hopefully it helped at least a little. Let me know what you find.

 

Sounds like you have a hard short in a circuit. What happened is, the hard short burned the fusible link. There are a couple of fusible links there at the relay. Now you have to isolate where the short is coming from. Do you know which link you blew? What is the wire color and tracer color?

 

its an orange line i can see where it hooked up but when I try to put it back on the wire glows red hot.its the positive side of the relay. theres the main pos. cable and 2 lines one runs toward the voltage reg thats the one thats bad.

 

Friend of mine told me maybe it was a direct ground short in the relay itself. Think he could be right?

 

Break out the ohm meter and start looking for a short to ground with the battery disconnected, it's a real good short if the wire gets that hot.

 

Allrite i did all that I traced the black/orange striped wire to the alternator.If I was correct pulled an ohm test all the way to there.There were 2 connections between the relay and there. cleaned them the whole bit , tested each connection put in a new starter relay still getting hot maybe my alternator???

 

yep alternator Cant believe it makes a wire that hot.

 

Must be a short to ground in/at it, let us know how things go.