Did I just fry the BCM?

[Ryno]

I had the Phoenix radio in my truck and for the second August in a row, it died. Decided I would switch back to a factory setup and ordered a UAV set up. It came in and I made up my own splitter cable with a plug and some taps. After hooking it up, I was able to get the AC back to working but the radio and screen would not. I start to troubleshoot, checking for power and everything else. In the midst of everything, I ended up hooking the screen and hvac plugs up backwards and turned the truck to run. My wipers come on and will not turn off, the traction control light is on, the engine light is on with various communication codes, service 4wd is on, none of the buttons on the steering wheel will work, and I’m back to no AC. I’ve checked every fuse inside and out, and the only thing I can think is blew out the BCM. Obviously CAN communication is down and I’m thinking it all goes back to there. Any help would be great.

 

[Ryno]

Well, I can connect to BCM through Alfa, no communication with ICS, steering wheel module, or radio. I noticed the ICS and steering module are on the same power circuit, but the fuse is good. Same with the radio fuse.

 

[ZombieSlayer]

Disconnect negative battery cable for a half hour. Reconnect and see what's what.

 

[Ryno]

I’m going to leave it unhooked overnight and see. Fingers crossed.

 

[Ryno]

No luck with that. Not sure what to try next.

 

[Ryno]

So I figured tha I connected 12V+ to the high side of the CAN IHS circuit. What I’m not sure of, is which module that originates from?

 

[ZombieSlayer]

Ok why did you need to make a splitter cable?

 

[Ryno]

Because you have to have one to go from the HVAC control to the display on the UAV. Unfortunately they are the same plugs, but with different pin outs. The later models have a different plug there, I had one from a 2019, which odd the same.

 

[Ryno]

Got home finally, and to my multimeter. Traced it back to the fuse block under the dash. I ended up disassembling the entire fuse block and upon putting it back together (I thought the PCB had burned up), I found a blown 15 amp fuse. I replaced it and now everything works (besides the radio, which was the original problem that kicked this off). Unfortunately, I don’t know which 15 amp circuit it was, I took pictures of the fuse layout and then took all the fuses out without looking at their condition. It was only upon installation that I caught it.

 

[kapinallinen2]

Any time I work on my truck, I run a go-pro as my copilot...