Dead Jeep On The Road..

[Ostego]

The ignition switch could be a possibility, but I would bet good money that you burned out a wire, fuse or computer while boosting the ford (that will teach you, never let your jeep touch a ford)

Lol. 2 AMC's and a Ford aint THAT bad. 

Well its defiantly something electrical we got tired of messing with it and swearing at it so were just gonna truck it in to the dealers and let them figure it out.

That's why I'm glad my J20 aint all computerized.

[jpthing]

They break because the melt.  They melt because they get hot due to the current running through them. When you look at current carrying tables, the shorter the wire, the more current they say it can carry.  The more area, the more current it can carry (larger wire) and soldering, for the part that is soldered, has more area.

Taking all that together, I'd deduce that the shortened, soldered link would fuse at a much higher current.  It would still fuse at some point, but so will regular wire eventually.

makes sense but those tables are generally in feet not sixteenths of an inch. I'm unsure how big of a factor length of a conductor is in it's resistance when you are comparing a 3/4 inch piece of a given conductor to a one inch piece of the same material...this I've never seen on the wire gauge charts and I'm not sure if  the difference in resistance/load carrying capacity could be measured without some very fasncy tools. Are you saying that a 1 inch and 2 inch piece of the same wire will showa  different resistance that is meaningful or measurable? Those tables are more about the ability of a conductor to carry current over longer distaces as far as I understand it.

I accept your deduction that the shorter link could theretically carry a higher current but I'm not sure if it would be "much" higher like you said.

It really wouldn't matter much if you replaced a 10 amp fuse with a 10.5 amp fuse would it?

[Waytec]

I am going through this right now with my MJ, we have now determined that the ECU is poached.

I started it up in the parking lot at work and it ran for a couple min then died. this is at 2am so I got a ride home and came back the next day. tried the basics. fuel - have some, started is roiling over, spark yes. but could not fix it. so on the hook to my buddies shop. put it on the scope and we found the injectors are not getting a signal. I had to go to work so he keep checking wiring and determined the ECU is done for.  

So there is another possibility. I don't know how you would determine if the injectors are getting signal without a amp clam or scope. I would not just pull a injector out and check.