ghetdjc320

These are standard GM bulkhead fuse blocks. Holes are a bit bigger and you can repin them as you like with the proper tools. I’ve been running my painless 24circuit universal in my MJ for some time now. Most of the circuits are fairly standard on the MJ column since they are GM with the exception of the wipers and hvac controls.

Awesome! That was the missing link. So it looks to me like those pins everyone uses for aux are just test points on the PCB. My current goal is to intercept the am/fm signal pre tone controls, and add a switching input that will pass through am/fm but switch to aux or Bluetooth when signal is present. I want to have this trick the radio into thinking a tape is playing so the radio station display goes away. Then have the play, rw and ff buttons trigger a DSP to skip songs and play/pause. That logic looks simple enough. I’ll add a transistor to transfer that logic to the DSP to trigger this functions. I’m liking the tinysine DSP boards with Bluetooth. I can have a clean aux input for my DAC and a Bluetooth for regular wireless pairing

Did a bit of signal tracing on the preamp board. Also desoldered the mounting plate for the volume and tone pots. I hadn’t noticed before that there are several adjustable potentiometers on the board. Two of them attenuate the tape deck input. How I would love a good diagram of the board lol

I was staring at the disassembled radio for a bit… Really wish I had the diagram or schematic for the RX series of radios. However, I’m wondering if, when the cassette is inserted into the deck it mutes or shuts down the radio tuner entirely, thus preventing the bleed through. I wonder if there is a way to emulate the tape being present when an aux input is applied. I’d assume there is some simple 12v or 5v logic commands that trigger the display to show tape commands. And since there isn’t really any input change command, I’m assuming this is just a logic curt unit that mutes the tuner or puts it in standby. I’ll either have to dig up a schematic somewhere or just get the multimeter out and test away. In a nutshell, here is what I’d like to accomplish on a mostly stock radio: 1. Eliminate the tuner bleed through without disabling the radio or attenuating the gain. For this I’m thinking simply intercepting the radio input to the preamp board in some fashion. A switched input jack would do the trick nicely. But an automatic method would also be nice. 2. Get the display to show different information other than radio station while playing aux input. Emulating tape deck display functions seems like the go to option here. 3. Get the stock play, rr and ff buttons to control the aux source. This one is a bit tougher with stock components.

Ive used those in the past. But those still use the FM radio tuner to carry the signal. I'm wanting to run the DAC signal direct to the pre-amp board and disconnect the tuner output altogether.

Just ordered up an RX-173 that seemed to be in good shape from eBay. will be tearing that one apart as well. There is one glaringly obvious solution that occurred to me for the am/fm radio bleed through when adding an aux input, a switched 3.5mm socket. It's a super simple device that passes through signal on normally closed contacts when there is no plug inserted in the jack and automatically switches inputs when plugging in a jack. Instead of using those two pin connection on the pre-amp board, why not just intercept the am-fm radio signal to the board? I do like bluetooth options as well but unfortunately apple still does not support any real HD bluetooth options such as Aptx HD. Therefore the best solutions tends to be a USB C DAC. Installing the DAC close to the head unit 3.5mm port would shorten the signal path. The connection would be USB to the DAC then switch to analog and go to the RX series radio pre-amp board where the am/fm radio would normally plug in. It's just a 3 pin JST connection for the stereo signal. If done properly with quality components, that would be the best audio signal one could get to the stock RX series internals. The DAC analog output may have to be attenuated down to the appropriate line level voltage to match the am/fm radio levels when switching. On the output side, a nice DSP would work great to not just make up for the stock amplifier limitations, but also to tune the cab acoustics. I'll post up how this works out. I think the current RX-172 I have I'll just gut entirely for a future raspberry pi setup with an OLED screen but the RX-173 I'll use to optimize a factory component system.

Notch flares are truly a horrible fit. They look great once finished but the fit is ridiculous. If you really wanted to, you could restore the factory spots by grabbing the key parts bedside repair panels and trimming out the fender mounting portion and welding it to your bedsides.

I've been considering that option as well. You could run a raspberry pi based system and an old or lcd display. Would be fairly straight forward to have it display metadata like bluetooth song info, radio station numbers/names (with an HD radio hat) and input names. If I was going that route (which I may lol), I'd just strip the entire guts out of the radio and use the shell, faceplate and probably the buttons interface once I've mapped them out.

Next up, I’m going to measure the am/fm radio module output voltage to the pre-amp. I’d like to install a tinysine Bluetooth module which has an audio priority line. So basically, the am/fm radio signal will first go to the tinysine module. The module will pass through the audio from the radio until it receives a Bluetooth audio signal. Once it does, it will completely block the am/fm input. This is in an effort to delete bleed through from the radio without disabling it. The issue we’ve had with this in the past is the output level of the tinysine module is 1.9vrms which overloads the pre-amp and introduces distortion. So I will introduce a line level attenuator to the signal to match that of the am/fm radio. Then I’ll tap the pre-amp output signal and run it through an active DSP board which will ramp back up my line level outputs from .6vrms up to +/-2vrms. Replacing the bulbs on the RX-172 LCD is tricky but not difficult if you take your time and don’t overheat the board desoldering the bulbs. The replacement bulbs for the actual button backlighting is a t1 style. I’ll post up part numbers here in a bit. Too much of this information has stayed elusive now for too long imo. Another option I’m exploring is repurposing the play/rewind/fast forward buttons to control the Bluetooth module playback. I’d map them as play/pause, skip forward and return. I’d also like to map an actual input switch. If I go this route, the priority audio pass through will be irrelevant. The ultimate goal here is keeping it looking stock but functioning like a newer unit and integrating a DSP for audio quality improvements.

Pics added

So... I've been digging through a recent RX-172 from a 92 MJ recently. I'm really just doing process of elimination signal testing. I've had many different ideas about what to do with these ready from custom Arduino with OLED interface in place of the stock LCD to installing a DSP amplifier board in place of the tape deck. From what I've been gathering, The main am/fm radio processing board is the large bottom PCB on the bottom of the radio. There is a 3 wire JST connection that feeds the pre-amp module with radio signal in basically an XLR audio format. There is another 3 wire JST from the cassette deck module to the pre-amp. What I'm referring to as the pre-amp is the small board that hosts the two pins that people are using for the aux input and the volume/fader and tone control pots. The actual amplifier board is located just behind the main radio speaker/power connector. I'm going to do a picture dump so everyone can see the insides in more detail. I have zero use for the tape deck. with the removal of the tape mechanism bracket, you now have a really nice mounting platform for a variety of PCB modules such as DSP's or Amplifiers. The radio board still needs power to provide the LCD with information to display such as the clock and radio station. Will add to this in a bit but for now here is a picture dump:

If It's the blank, those were normally just a thin plastic bezel that was attached to the larger gauge cluster bezel. You can also get 3d printed aftermarket ones that will just have a couple of carling style rocker switch holes. Or you can grab the switch holder from any 96- XJ or MJ that had the actual switch holder there. Somewhere, I have buckets of them lol.

I’m thinking something like this could be made to work: https://vwispwest.com/retaining-clip-arm-rest-for-quarter-panel-311867289/

Are you trying to get it back to stock or keep a 4” lift?

I think we all know that there are only a handful of manufacturers and I’m not saying that a quality product cannot be had from China as we all know it can. However, back to the original question, any info on Axiom? @golddigger, any information or experience with them? As for timken or SKF, they still are oe design. The question is whether there is a truly superior engineered product available (which Axiom claims to be). Something that can stand up to heavier tires and less wheel offset which tends to kill oe style units. I’ve bought many a Timken bearing over the years but the last two sets I purchased did not last at all and started to become noisy within a few thousand miles. One on my MJ with 33’s and one set on my TJ with 30” tires. Keep in mind that I run the 99.5+ style unit bearings for the slightly different offset and longer lug studs. In the TJ world, these are the Timken units that seem to be having higher than anecdotal failure rates recently, and the timing is suspiciously close to when production moved. Of course, there also appear to be counterfeit Timkens floating around. I haven’t had any premature failures with SKF so far. But again, the question here is Axiom