Carpokes

Hi all,

Any radio experts around here? I am in the process of redoing the radio wiring in my car, plenty of questionable mickey mouse type stuff from whoever installed the previous unit. I am stumped about what to do with the brown ground wire pictured below (need to go from the large ground wires to a small 16-18 gauge wire).
For starters, I don't have any "step down" connectors to go from stranding both of the brown ground wires to a single small 16-18 gauge wire. Secondly, there appear to be grounding bolts present already in the radio area that are quite tempting as an alternative to the provided ground wires (circled below):
Anyone have any past experience with grounding the radio at the circled bolts? Or would I be safer to go with the brown ground wires? And why are there two ground wires anyway?

Thanks,
Drew

Not as familiar with the later cars like yours, but I was able to make adapters for my early car wiring to a modern radio without hacking up the original wiring. The speaker connectors were the worst, but female connectors for them were available on ebay.

I can confirm that the bolts you circled in the picture work fine as grounding points.

There are some very good reasons to ground all the audio components to the same place. This is most important when you have outboard amplifiers, so that there are no "ground loops" to contribute to alternator whine. For most of our cars, the brown wire in the radio harness goes to a chassis ground point, while those two bolts don't appear to go into the chassis.

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I decided to avoid any wiring hacks on my own car. The idea is that all the original audio components can go back in painlessly. And because the replacement system is a bit more capable, new larger wiring needed to go in to handle the higher current demands for power and speakers anyway. I know it's a little late for your car at least as far as maintaining the original radio wiring integrity, but think about adding new capable wiring for your replacement hardware. Even if you don't plan to add amps or upgrade speakers, add the low-level signal and speaker wiring needed for that now. Document everything, so you and future owner/victims will be able to diagnose and upgrade the system.


My too sense....

Interesting, I guess the brown wires it is in terms of properly grounding everything. Would soldering / heat shrink be the best method to "connect" the large ground wires to the small 22 AWG black wire as pictured below? A step down crimp connector seems to be out of the question due to the large disparity in wiring size between the two:
Again, I am not certain on if I can just ground the black head unit wire to a single of the brown ground wires, or if I would instead need to strand both brown ground wires together, along with the black head unit wire.

Here is the questionable solution that was taken to install the previous radio:
Definitely want to avoid doing a job like this if possible, just looking for the best solution. My guess would be a strand / solder / heat shrink job, what do you all think/recommend?

-Drew

If helpful, here is the factory wiring diagram. Note that there are several brown wires with stripes that are for the speakers, not power per se. In that first picture you posted, the wires look like they have stripes -- if so don't use those to power the new radio. Look for one or both of the big thick solid brown (no stripes) wires. It looks like there are two --one for the radio and one for the equalizer, but they are both the same ground, so you'd only need to use one to supply ground to the new radio (although using both wouldn't hurt anything). I would not use the center console bracket bolt as ground -- it would probably ground the radio but less than ideal for a lot of reasons (and not needed).

There is an eternal debate about soldering vs crimping on cars. In theory, perfect crimps can be better because they are less prone to fraying wires. But it's nearly impossible to get perfect crimps on things like this, so I always default to soldering and covering with dual-walled adhesive lined shrink tuning. The dual walled tubing kind of braces the wire around the solder, mitigating the risk of stress fraying where the wires would otherwise tend to bend back and forth over time. That's what I'd recommend here.

Thanks for the helpful advice as always Tom,

I confirmed that the brown cables did not have a white stripe, definitely ground cables in the picture.

I hooked up everything to the radio, turned the ignition to accessory, and...nothing. Confirmed that the head unit isn't bad, as I was able to get it to power up outside of the car connected to the battery, must be some sort of power or wiring issue on my part in the car.

I will have to test the green (accessory power) cables to confirm that I am actually getting 12V in the accessory position. Hopefully this isn't a deeper electrical gremlin that will start taking over the rest of the (mostly operational) car

-Drew