How do i find the short from the 4 hole 3 wire plug from the alternator? new alt and new batt but alt keeps getting super hot when that is plugged in?

Did you test the new alternator before putting it in. May be bad. Once you put it in turn the key and it self energizes unlike the older cars like vw. So if you forgot a wire or a plug to the alternator if it's good. Once the battery is connected it should be all set. So if that's not the problem you have to start looking for bad connections or melted wire and shorted a online fuse. Check your fuse box for any bad fuses.

The temperature of the alternator is not read by the engine temperature gage. It gets hot because it is most likely trying to charge a battery that is failing, have it electronically tested by a auto parts store like Autozone or others, it is a free test.

Make sure you reconnected ALL of the wires on the alt. There is more than just the pronged plug which only goes on one way.

Alternately, there could be a problem in the charging system like you suspected a short or broken circuit between the alt and the batt.

have you tried cleaning the batt terminals and make sure the plug on alt is in and the bolt that holds the one wire is tight in the alt

The regulator inside the alt. is bad. Replace the alternator.
When you unplug the the small plug youre running on battery. If you plug it in you can start a fire or blowup the battery.

A short in the wiring or depending on the amount of driving you do a bad alternator.

1) check 10A fuse in the batt. juction box (eng. comp.) hot at all times.
2) check the large red battery wire to the alt. for good conn.
3) make sure the alt. is grounded properly
4) gray wire sent from the alt. to the PCM
5) blue wire sent from the PCM to the regulator (alt.)
6) small red wire power frorm the 10A fuse
if all checks out and still not charge replace the alt.

Disconcet the positive cbl on batery..
Disconect plugs & wires from alternator..
Loosen the belt.
Undo bolts..
Pull out alt..
Put in the new alt..
Tighten bolts & belt.
Plug wires back in..
Re-conect cbl to batt..

Hope this helps !!
rate me good ;o)

First check alt At The Back of Alt Big Red Wire Were hooks to Post (stud) Do you have voltage ?? How Much??
What Voltage do you have at same Place with Engine Running ??
Now At wires Were they plug into Alt ,Top. Wires in White Plastic Clip, Do You Have Powe With Key On ?? How Much Voltage??
Jump across the 2 in the clip (with Engine Running)ONLY TEMPORARY!! Do You Have Voltage at Battery ?? How Much??
If Over 13volts With Clip On (Jumped) You Need A Internal Voltage Regulator ..
Is Batt Light On on Dash ??? Theres A Lot Of Testing You Can Do !!! And I will Need More Infomation to Keep Going ... These are just some Possible Problems No Way In Depth ...
Could Be a Number of things Or May be Just as Simple As a Blown Fuse, Dirty Batt Cables ETC etc etc I Hope It Puts You On The Right track !!!!!!!!!!

disconnect batt.remove air inlet tube over alt.remove serpintine belt.remove the alt bolts 2 in frt,2 or 3 in bracket on back.disconnect power wire + plug.change alt.reverse procedure to install.easy job.