The lead that gets hot is either defective (most likely) or you have something bad happening. I think the negative lead goes 2 places, chassis ground and a ground near the starter. There may also be one near the PDC (power distribution center). Don't bother to repair it, just go to your favorite store and get a new one with the appropriate length and lugs. The heat indicates a resistance, as the positive remains cool, it is probably OK for awhile. (Remember they are the same except for the colors, they have a life expectancy of X and it too will fail within a short period of time.? As for the voltmeter going to max, that could be a serious issue. After you get the new negative lead installed, remove the radio fuse. Start the car and check the meter, if it goes max shut it down immediately. Get a real voltmeter (preferably one with a "max" hold and attach it to your battery). If you're not familiar with this, skip the meter, buy a box or two of donuts and go the base ET or EM shop and look to see if there is a Jeep outside. Take the donuts to the Chief and ask for assistance. (A quick rule of thumb, meters and ET's good, guns and Marines good, switch these around and "bad 'tings hoppen mon"). The alternator is driven by the ECM, if it goes bad you will get at least 19 volts from the alternator. It will make "bad 'tings hoppen" to the lights, radio computer etc. Can you guess how I know this?
Happy New Year
Well I feel like an idiot. The problem was the neg terminal was rusted out underneath. I cleaned the outside, but I never unscrewed it and checked. I spent an hour cleaning it with a wire brush, then reattached and it worked.
I found it by doing another ohms check. The pos to neg was 40, the pos to the ground that was past the neg was 0. This told me that the terminal was bad. When I checked this before it wasnt doing this, so I hope this is the only problem with it.
I really appreciate everybody helping me fix this, and will be sure to help the next person who has a problem like this.