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Factory OEM SiriusXM nearly working in Tesla 2022 Model 3
- Thread starter sparkywatts
- Start date
@sparkywatts What is the Farka adapter required to convert the Model 3 FM antenna plug to the dual one on the MX tuner?
If you don't already have an existing sxm antenna this might be worth looking into
Its important to note that the sxm tuner in that silver box floats above main harmon tuner and it communicates through the pins that are unpopulated on the first image. That silver tuner box actually looks similar to the part used in other radios that have sirius.
Nope I just changed the housings, the rivets are a pain to drill out. I saw one of the chips didn't have a heatsink metal covering it, so I took a spare heatsink for a raspberry pi and used that to help cool the chip that the old housing didn't quite cover.
I looked into it a bit more and switching the sxm antenna made my sxm now completely usable, so that's good at least. Getting the fm reception to not suck I am still trying to figure out though. I looked into the service diagrams and it appears that nothing externally powers the fm amplifier, so I suspect its powered over coax. One of the chips on the board also makes me think that as well. On the opposite side of where the tuner is, the antenna amp connects to the same ribbon "backlight" as tesla calls it type connector going to the windshield. I suspect that one could use another antenna amp on the side with the now disconnected cable and then a fakra double to two - fakra singles adapter and then both antennas would be hooked up.
so basically, add a second antenna amp over on the same side as the tuner itself, connect the ribbon cable to the amp and then connect the fakra from the amplifier and the fakra from the glass to a double fakra to the tuner?
@stutech Thanks for your help. Have you tried the SXM original antenna with this adapter:
I was going to go with that setup
I was going to go with that setup
So I am just spitballing here but the Model 3 uses a different kind of antenna for FM tuning, so it may be a different impedance or is somehow imbalanced on the tuner circuit for the Model S/X.
Meanwhile, the Model S/X has two antennas, one of them that is also used for AM.
My guess is that the FM2 adapter is for HD radio while the AM/FM is for regular tuning. Maybe it needs both antennas for full strength? I'm out of my depth here and I barely understand these diagrams....
EDIT: Also the antennas themselves appear to have an amplifier circuit. I have no idea how it gets power over COAX.
EDIT 2: I don't know if this is helpful to anyone, but apparently there is a common method of delivering power to an integrated amplifier at the antenna over COAX. This details how it works in satellites. So maybe the FM antenna isn't getting the power it expects?
EDIT 3: Okay, I think I figured it out. I believe the Model 3 FM antenna is getting power over coax with the tuner. The Model X is getting power from the defrost grid I think:
There is also a filter module, which I guess might handle the dirty power coming out of a big grid that picks up all sorts of RF? So to get the tuner working properly with FM, I think we need to supply the stock amplifier with the power it needs over coax... somehow... or use the Model X/S antenna amplifier with 12V supply. I could also be completely wrong and the grid is just the antenna, and the Model X amplifier module is getting power over coax too...
Meanwhile, the Model S/X has two antennas, one of them that is also used for AM.
My guess is that the FM2 adapter is for HD radio while the AM/FM is for regular tuning. Maybe it needs both antennas for full strength? I'm out of my depth here and I barely understand these diagrams....
EDIT: Also the antennas themselves appear to have an amplifier circuit. I have no idea how it gets power over COAX.
EDIT 2: I don't know if this is helpful to anyone, but apparently there is a common method of delivering power to an integrated amplifier at the antenna over COAX. This details how it works in satellites. So maybe the FM antenna isn't getting the power it expects?
EDIT 3: Okay, I think I figured it out. I believe the Model 3 FM antenna is getting power over coax with the tuner. The Model X is getting power from the defrost grid I think:
There is also a filter module, which I guess might handle the dirty power coming out of a big grid that picks up all sorts of RF? So to get the tuner working properly with FM, I think we need to supply the stock amplifier with the power it needs over coax... somehow... or use the Model X/S antenna amplifier with 12V supply. I could also be completely wrong and the grid is just the antenna, and the Model X amplifier module is getting power over coax too...
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Well, I guess I hit the edit limit on my last post. Ignore all that please.
The antenna is integrated into the grid, both in the Model X and the Model 3. There is an inline splice/adapter/??? that takes the single coax line from the right side of the Model X and the two coax lines from the left side, consolidating the FM lines into one and the AM/FM into the other.
As for the power of the amplifiers, I don't see any circuit diagram that it is pulling from the defrost grid, so my guess remains some sort of power over coax. I cannot make heads or tails of the wire harness (4072429-XX-A) so I have no idea how it combines 3 separate lines into 2, and then somehow delivers power to the two amps. Either way, I believe understanding that is key to resolving the FM amplifier issue.
The antenna is integrated into the grid, both in the Model X and the Model 3. There is an inline splice/adapter/??? that takes the single coax line from the right side of the Model X and the two coax lines from the left side, consolidating the FM lines into one and the AM/FM into the other.
As for the power of the amplifiers, I don't see any circuit diagram that it is pulling from the defrost grid, so my guess remains some sort of power over coax. I cannot make heads or tails of the wire harness (4072429-XX-A) so I have no idea how it combines 3 separate lines into 2, and then somehow delivers power to the two amps. Either way, I believe understanding that is key to resolving the FM amplifier issue.
I can tell you just from my own tinkering when I installed my onyx years ago that the black ribbon connector has something to do with powering the FM antenna amp. with it connected to the original tuner, reception is strong...as soon as you disconnect that one line, it takes a huge hit.
AFAIK The ribbon connector is for the antenna itself so I think that is removing the antenna rather than the power source. Could be both though, maybe the antenna is at a 12V bias?
I played with it some more here, and I did get decent fm reception now! So what I I didn't realize is the adapter I bought that combines the two fakras to one has the correct pin length on the double side, but on the side that's single the fakra connector length and pin size are mismatched. I modified my adapter and crimped the correct size fakra on, and also made it not combine to a single, but instead made it two single fakra outputs combining into the double connecter going to the tuner. I then put a small fm antenna under the rear trim behind the seats that connects to the second fakra crimp I made on my adapter. Now my reception is stronger than ever, I used to have static in the garage as I am in a somewhat rural area, but now that's fixed. Fyi for sirius make sure you put a metal plate under your patch antenna or mount it somewhere with a lot of metal underneath. In my case I mounted it on the rear speaker shelf under the cloth trim liner. Theirs some space there to hide the patch antenna from being too visible under the rear speaker trunk liner. I plan to get the other factory window antenna going instead of my make shift second one, but its working for now and slightly better than the tesla one ever did. I believe the driver side antenna amp is turning on via power over coax now, as it gets warm suggesting there is power. For the antenna filter wire, if you swap the cases for the board like I did, you will have a place to attach it still. I believe all that does is add a grounding point to the body and amplifier to help filter emi noise while charging.
Dual Fakra Car Antenna Adapter by Keple, Double Fakra Vehicle Aerial Connector for 3rd Generation Radios in RCD, RNS310, RNS, MFD Radio, Twin Fakra Adaptor https://a.co/d/iLwuOH4
This adapter?
