Help: Troubleshoot aftermarket head unit issues

[e46fan]

I apologize in advance if I come across short, I'm not in a good state mentally. I've been prepping my 4th Gen with 150k miles for sale and have gotten all the little nagging fix-it items complete over the last couple weeks. I was ready to list it, however I wanted to have my buddy do one last detail to shine her up good before I took some pictures of her. When I was on my way over to pick it up he said he must have left something on overnight because he had to jump it this morning and be prepared to jump it again before I left, just in case. Sure enough I got there and it was all "click, click, click". We jumped it and immediately I noticed my HU wasn't powering up. It's an aftermarket Pioneer double din with a backup camera I put in (I can add model number later). Anyways it has a detachable face so sometimes if it is taken off or put on incorrectly this happens, so I was kind of mashing around on the front to make sure it was seated and it flashed for a second and went dark for good.

I checked all the relevant OEM fuses in the car, then began the tedious process of taking the dash apart to get at the head unit. I got it all taken apart and confirmed that the screen was seated properly but appears to be getting no power. Now I'm kind of stuck as to what to do next. Can anyone help me out?

Thanks in advance.

 

[e46fan]

I apologize in advance if I come across short, I'm not in a good state mentally. I've been prepping my 4th Gen with 150k miles for sale and have gotten all the little nagging fix-it items complete over the last couple weeks. I was ready to list it, however I wanted to have my buddy do one last detail to shine her up good before I took some pictures of her. When I was on my way over to pick it up he said he must have left something on overnight because he had to jump it this morning and be prepared to jump it again before I left, just in case. Sure enough I got there and it was all "click, click, click". We jumped it and immediately I noticed my HU wasn't powering up. It's an aftermarket Pioneer double din with a backup camera I put in (I can add model number later). Anyways it has a detachable face so sometimes if it is taken off or put on incorrectly this happens, so I was kind of mashing around on the front to make sure it was seated and it flashed for a second and went dark for good.

I checked all the relevant OEM fuses in the car, then began the tedious process of taking the dash apart to get at the head unit. I got it all taken apart and confirmed that the screen was seated properly but appears to be getting no power. Now I'm kind of stuck as to what to do next. Can anyone help me out?

Thanks in advance.

Head Unit is Pioneer AVH-x8500BHS if it matters.

 

[e46fan]

Head Unit is Pioneer AVH-x8500BHS if it matters.

Continuing my troubleshooting. For grins I hooked up my old (stock) head unit. It worked like a champ. I'm guessing this means that the fuses in line are all ok? There is a fuse on the back of the new HU but it doesn't appear to be blown. I'll replace it anyways when i get out today.

 

[e46fan]

Continuing my troubleshooting. For grins I hooked up my old (stock) head unit. It worked like a champ. I'm guessing this means that the fuses in line are all ok? There is a fuse on the back of the new HU but it doesn't appear to be blown. I'll replace it anyways when i get out today.

Well, I'm already committed now so I guess I'll just keep documenting my troubleshooting for others out there - you know, to help others that have issues.

Went to auto parts store and got a fuse to replace in head unit. The old fuse was a little "brown" around the leads but the bridge was in tact. I replaced, no bueno. I did get a fuse tester as well so that is my next step to test all fuses related to operation. After that I'll get the multimeter and the youtubes up and try and test out voltage to the HU. There is also a "reset" procedure I was reading about in the owners manual that I will try. Finally, if all else fails, I may run a separate power to the HU with fuse in line just to make sure.

 

[riceandpho]

i check the wiring harness and see what was used to hook up with the oem wires. also a firmware upgrade might be needed. it would help with a pic of the headunit wiring.

 

[e46fan]

i check the wiring harness and see what was used to hook up with the oem wires. also a firmware upgrade might be needed. it would help with a pic of the headunit wiring.

First off - thanks for responding! I really appreciate it.

Secondly, I got it resolved. For those that may need this info in the future, here is what I did.

1) Freaked out, felt hopeless and lost, called Crutchfield (where I bought the HU 4 years ago). Dude, they were amazing. The tech I talked with walked me through some stuff I tried and confirmed some stuff, but also gave me lots of good ideas. I can't say enough good things about them and they have made a lifelong customer.

2) I was concerned the fuse was blown on the HU. Tech said if that fuse was blown, then it was game over for the HU. It's basically just fire supression at that point. I took the old fuse, that didn't appear to be blown but did look a bit "brown" and put it on a multimeter. All good. At this point I think there is still hope. Either way, I ran to auto zone and got a fuse and replaced just in case. Tested, still no bueno.

3) I went online and found how to bench test HU. This is where you hard wire up either via the wiring harness or just pinout direct to the (a) car battery. I didn't want to undo everything in the car so I spent some time and made a three wire harness for the HU including power, ground, and accessory wires. I hooked this up to the car battery and still nothing.

4) Then I tried something I found in the HU manual, a "reset" procedure. It was very vague on what it did, and the tech wasn't hopeful, however it was my final shot before throwing the old HU in or buying a new one. I pushed the reset button during power cycle, and wiggled wires a couple times. After a few different sequences the unit came back to life.

5) I figured I was out of the woods at this point so then i just hooked it back up to the wiring harness in the car and again, it came back up. So all good. Then i just had to put the HU back and all the trim pieces back.

6) Beer.


tl;dr - There is some weird internal software failsafe switch that got tripped and this mystery "reset" procedure fixed it.

*edit- forgot multimetering

 

[riceandpho]

i still think its a bad connection with a couple of wires, depending on how the wiring is crimped or solder, it can contribute to all sorts of problems.