Had electrical accident, radio doesn't work. How to troubleshoot?

[beowulf_lives]

A few months ago, while replacing the wiring to the MAF sensor, one of the wires touched the positive terminal. Worse, the negative terminal was touching the negative battery post, creating a short circuit. What I noticed first was a squeal coming from the general area of the EGR before I saw the wiring mistake. I finished the repair and, holding my breath, started the car. Everything worked - including finally the MAF - but the aftermarket radio was dead.

All the fuses in the engine bay and in the hidden compartment near the steering wheel were checked with a multimeter and they all passed. The radio fuse also passed. Since it's aftermarket, there's an extra fuse in the wiring loom for the PAC C2R-VW2 CAM "thing," which also checked. I couldn't find a continuity problem in the wiring there, however I replaced the radio and the PAC C2R-VW2 CAM "thing" hoping that would solve the problem.

The control lights on the new radio come on, but the display itself doesn't and there's no audio. The radio is not exactly the same, but it's the same brand and the wiring is the same as the old one. Ideally, testing with the stock radio would eliminate a few variables, but I don't have one. The car didn't come with an amp under the driver's front seat.

I could use some guidance on where to go from here.

 

[privateTDIjet]

A few months ago, while replacing the wiring to the MAF sensor, one of the wires touched the positive terminal. Worse, the negative terminal was touching the negative battery post, creating a short circuit. What I noticed first was a squeal coming from the general area of the EGR before I saw the wiring mistake. I finished the repair and, holding my breath, started the car. Everything worked - including finally the MAF - but the aftermarket radio was dead.

All the fuses in the engine bay and in the hidden compartment near the steering wheel were checked with a multimeter and they all passed. The radio fuse also passed. Since it's aftermarket, there's an extra fuse in the wiring loom for the PAC C2R-VW2 CAM "thing," which also checked. I couldn't find a continuity problem in the wiring there, however I replaced the radio and the PAC C2R-VW2 CAM "thing" hoping that would solve the problem.

The control lights on the new radio come on, but the display itself doesn't and there's no audio. The radio is not exactly the same, but it's the same brand and the wiring is the same as the old one. Ideally, testing with the stock radio would eliminate a few variables, but I don't have one. The car didn't come with an amp under the driver's front seat.

I could use some guidance on where to go from here.

Ive had a 2006 before and had the radio harness wires all touch eachother (ouch). It ran fine until it randomly died on me on a highway overpass. What my problem ended up being was a faulty relay on the main relay board where the pedals are.

What if your aftermarket radio simply crapped itself? Some aftermarket fuses are terrible at their job so I wouldnt be surprised. I suggest you test out an OEM one for now to isolate the problem to either the car or the radio itself. I bought a premium 7 radio for CAD 10$ off of marketplace so prices arent unreasonable. Maybe even ask someone with one if you could try it out.

If you isolate your problem to the car, check out if any codes are stored on VCDS. I could help you with wiring diagrams for your car if you need help with identifying circuits.

 

[beowulf_lives]

Hey thanks for the reply.

I could never find anything wrong with the car relays or wiring and I still don’t have VCDS. I do need to buy it.

Ended up just buying a new radio the other day. I wired it to the replacement PAC C2R-VW2 adapter and all speakers and display are working.

The original radio died from the electrical short circuit, but why the second never worked when it had the same pinout as the original? I am just so over it.

 

[beowulf_lives]

Btw How did you troubleshoot that? Tracing as far back as the relay panel you mention.