30M APRS works, but it almost breaks the truck!

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I installed the 30M APRS system today and APRS works great. I saw it gate at https://aprs.fi in both Brownsville, TX (300mi away) and Sugraland Run, VA (1290mi away, as the crow flies!). I was playing with TX power between 30w and 150w, so I’m not sure how far it travels with how much power. Of course I think that’s subject to a lot of conditions other than power.

Where this went wrong is shortly after installing it and getting it working properly, my truck began intermittently losing power. After a little while longer, several alarms popped up including ABS, StabiliTrak, Park Assist and Trailer Brake Controller malfunctions. I thought it was the radio, but after turning it off, pulling codes (none found), and clearing them anyway, the lights remained. It also seemed to have come on right after hitting a bump at 35mph, so I thought maybe something pulled loose. I spent a couple hours under the vehicle double checking all of the connections that seemed as if they could be related to those specific errors, but all were fine. I started the truck again and the lights were still on. After a while of idling while I searched online for potential fixes, the light went off.

With the light off, I began experimenting with the radio configuration. My findings were:

• 10.147.60USB (APRS freq), 30w transmit, no noticeable changes
• 10.147.60USB (APRS freq), 50w transmit, noticeable dip in truck power only when beaconing, no lights or warnings
• 10.147.60USB (APRS freq), 150w transmit, lights/alarms come on after approximately 3 beacons
• Keying up manually on 10.147.60USB does not seem to cause issues, but testing here was limited because it is data only
• Transmitting, even at full power, on 14.213USB does not cause issues
• Unplugging only the DATA port of the TS-480HX (TT4 connection to radio) ceases issues
• Several (unmeasured) minutes of idling clears the alarms

Since I don’t need HF APRS most of the time, I decided to leave it unplugged unless needed. I’m not really sure where to troubleshoot from here or how to fix this, aside from the several RF chokes I already tried (improved, not fixed the issue, and I don’t think chokes are the issue at this point.) When I do transmit, it seems 30w is going to be the practical limit unless I can find ways to eliminate the interference. I ordered some more RF chokes and ground straps to try.