Electrical Gremlin--Quick help needed please

Ok, while driving my stereo starting turning on and off, my fan speed switch did not work and my blinkers quit working. When I got to my first stop, the vehicle (91 XJ, 4.0, 4x4) was only off for approx 10 min. Would not start. Jumped it and drove it to next stop.. died while pulling into the parking lot. This time I smelled something and upon further diagnosis I found what I believe to be the problem.. I just need help identifying what exactly it is. It is a box mounted on the passenger side fender right behind the battery. I do not believe it is stock but I believe i have seen pics of XJs with similiar boxes in same location. It appears I have a 1 wire Alt and the wire is run through the box. A few weekends back I had the box open and it appears to have 3 relays in it, but they are all wired together and are not removable. While running I am only getting 9.5Volts at the battery, when not running I get 12.5volts. I am not sure the accuracy of the multimeter as it is old and has been abused. I check my wife s-10 blazer and it registered 18 volts on hers. Regarless of the accuracy there is a voltage drop while running. The box also gets too hot too touch. I realize the under hood temps of an XJ are fairly high but this is considerably hotter than anything else under the hood...

What is it? My father who is a Jeep parts salesman hasnt been able to find anything yet..
Can I just wire it straight to the battery? The XJ is currently on the side of the road as it go so hot it would not run for too long.

PLease HElp.

JOn

And sorry no pics available, the XJ is on the side of the road and did not have the camera with me.

Well after further review the ALT is NOT a 1 wire Alt, the other wires (3?) were just tucked up well underneath it. Wife pushed me home 7-8 miles.... but what the heck is it? I will take pics tomorrow...

Ok well I do believe it is an external regulator. After culsulting with some mechanics in my office and a bit of web research I believe that it is. However, my Jeep shouldnt have one. So now I will test my alt to see if it is internally regulated and see if perhaps the alt went out too and over charged causing the external regulator to fry. Below are some pics from the web that look almost just like it except mine has 3 "switches" on the inside, but the cases looks almost just like eachother.

that is a regulator-- did that come off your Jeep?

Those are pics I found online but the one on my Jeep looks alot like it except it has 3 "switches" inside instead of 2...

It's an old G.M. regulator. I'm not sure why it was installed on your rig, but if your alt. has the B+ wire and three more in a plug, yours is internally regulated. I would either replace the old regulator and see if everything functions, or remove it and rewire (use factory wiring diagram) the charging circuit to work as designed-- you'll probably end up replacing the alt, as I'm sure someone band-aided it together for some reason.

IIRC, the three wire plug should have one constant "hot" wire, one "hot" with the ignition, and a signal wire for instrumentation on the dash.

--Shorty