Factory Radios for 87-89 Ram 50/Mighty Max

[StarquestMan]

I should add for anyone else that may find it useful, when i checked my 87-88 parts catalog it lists the digital 4 speaker radio for these trucks as being part number MB488544 this is incorrect since it is the orange illuminated J892 used in the Montero/Raider that MrPaco mentioned in a previous post. The radio he bought can be found in Colts and Colt Vistas of similar vintage and so far we haven't been able to figure out what the difference is between these radios and the MB541097 J989 4 speaker ones that came in our pickups and strangely my catalog doesn't even list the MB541097 at all for any vehicles even though i know mine came from an 88' Ram 50. I was talking to MrPaco earlier and I had mentioned that the J891 may have a slightly higher power output to drive bigger speakers in a car or a different EQ circuit board to change the sound output to suit a larger interior but this is just a wild guess.

[MrPaco]

The bass and treble knobs work properly,they do the job. The sound coming out of it is probably as good as can be expected from a 30+ year old stock radio, it's definitely not a high end stereo, but it sounds very good.
The fader knob works, but I would say that it only takes the power down to about 10% on the opposite speakers to where the knob is turned to, it doesn't silence them completely. The balance knob doesn't seem to be doing anything, sound comes out of both sides no matter where the knob is turned to.
Is it possible that these two knobs are functioning funny because the speakers in the truck are undersized for the radio, maybe?
In any case, it doesn't make a difference, I have no need to balance or fade the sounds from one side of the cab to the other one. Come to think of it, I don't know why anyone would need to do that anyway.