RazzMaTazz

I have a 2007 Equinox LS. No moonroof. No power or heated seats. I want to add a Bluetooth receiver dongle (which probably draws less than .5A) to an ignition-switched fuse (preferably an unused one) so that the Bluetooth dongle doesn't drain my battery when the car is off. I probed a few of the fuses inside the passenger compartment with my volt-ohm meter but they all seem to be unswitched. Suggestions please?

FYI: Ideally, I'd like it to be tied to the radio's power so that the music stays on until I open the door. But even the radio's fuse seems unswitched. Maybe I'm doing something wrong.

Here's the passenger compartment fuse box diagram.

ruley73

The radio's power is unswitched because it is commanded to turn on/off by the BCM.

Your best bet is to tap into a RAP (Retained Accessory Power) circuit. As you'll see in the diagram below, this includes power windows, rear seat entertainment (RSE), and the sunroof. I just went out and tested some things with a voltmeter. I found that the bottom fuse terminals of the RSE and S/ROOF fuse sockets are still live even though our Equinox is not equipped with these options. You'll want to test the terminals on your Equinox to confirm this, but I'm betting yours will be the same way. Assuming this is true you could just use purchase a mini fuse tap from your local parts store and insert it into one of these sockets to get power to your bluetooth dongle.



Because your power supply is from the RAP relay, your bluetooth dongle will be switched by the BCM just like all other items in this circuit. This means it will turn off after 10 minutes or when any door is opened. The radio is slightly different because the BCM turns the radio off after 10 minutes or if the driver's door is opened (unaffected by other door ajar events).

RazzMaTazz

Thank you! Thank you! Thank you!

1) RSE & S/ROOF are indeed switched.
2) I didn't know about mini-fuse taps. Great tip! $6.99 at my local parts store. Well worth it. I had always just jammed a wire (with an inline fuse) into a fuse plug.

FYI only in case it helps others...
What confused me previously was that the RSE & S/ROOF fuse slots read about 3V-- not 12V-- for a few minutes after the door is opened. But thanks to your comment about things turning off after 10 minutes, I found that they eventually drop to 0V when ignition is off. Weird that it's not 12V. Maybe some kind of capacitive or inductive leak?

I was also surprised to see that some slots, like "heated seats" never dropped to 0V-- even after 20 minutes or so. I would have expected heated seats to be ignition-switched, but if not, at least to turn off after some period of time in order to prevent battery rundown. Maybe the computer only shuts stuff down if it's drawing current?

RazzMaTazz

Just in case it helps others...

This worked better than I expected, and exactly the way I wanted. Surprisingly, even though I tapped into my (otherwise unused) sunroof fuse slot, the attached USB power adapters retain power until I open the driver's door (just like the Equinox's stereo). Then they shut off. So there's no battery drain from my USB power adapters-- unlike when they're plugged into the Equinox's cigarette-lighter ports.

FYI, in case it helps:

1. I added a mini-fuse tap ($7) to the sunroof (#1) fuse slot and gave it a 10A fuse (alongside the sunroof's unused 20A fuse).
2. I connected a 3-port (cigarette-lighter) splitter ($5).
3. I inserted two 3-port USB-power adapters ($2 each) for my family's USB power needs, and I secured them to the ports with packing tape so they wouldn't shake loose over the coming years.
4. I concealed it all in the space behind the fuse box (under the gear-shift).
5. I attached a Soundbot SB360 stereo Bluetooth receiver ($20) on the dashboard next to the steering wheel, and fished its (output + USB power) cabling into the fuse box area. Neat-looking with practically no wire showing.
6. I attached a female-female coupler, and a male-male cable from the Soundbot's headphone plug output, inside the center console, popping it out near the glove box and connecting it to the AUX input of the stereo. (Nice & neat looking.)
7. I fished 3 micro-USB cables ($1.50 each) from the USB power adapters to convenient locations for the driver & front passenger. (One into the glove box and 1 at each of the map holders on the center console.)
8. I fished/tucked two 6' male-female USB cables ($1.50 each) from the USB ports under the center console, popping them out near the rear post of each front seat so that the female-USB end can be used by the rear passengers or stored in the bottom of the center console.

Now...

• My (battery-less) Bluetooth receiver automatically turns on when I turn the key (which is why I chose the Soundbot SB360 instead of cheaper receivers with rechargeable batteries that you have to manually turn on).
• My phone automatically connects via Bluetooth in ~5 seconds.
• Music automatically plays from my phone via Bluetooth (because I have my phone set to do that).
• I can make & receiver hand-free calls via Bluetooth.
• Power is supplied to conveniently-located USB ports for me and my family.
• Music and power remain on until I open the drivers' door.
• It all shuts off (with no battery drain) when I open the driver's door.
• My rear passengers (usually my kids) can attach micro-USB or iPhone cables to the female end of the USB cables that I ran to the rear.
• No more USB-cable mess.
• No more plugging & unplugging a USB power adapter that is inconveniently located under the cup-holder.
• No more dead phones because the USB power adapter wiggled loose while driving.
• No more broken USB power adapters from my kids bumping into the rear port.
• No more dead-battery if any of us forget to unplug the USB adapters.

Perfect!

Thanks again to Ruley73!

ruley73

I'm glad that this worked out well for you. Thank you for following up. I would suggest using a smaller 5 amp fuse. You always want to use the smallest fuse you can as long as the circuit's peak current draw doesn't exceed fuse rating. This will protect the circuit in the event of a short, and at the same time prevent the fuse from popping during normal use. I'm estimating that your circuit's peak draw will be about 40 watts if you are using your Bluetooth device and charging three tablets at the same time. That's about 3.33 amps at 12 volts (40 ÷ 12 = ~3.33). Based on that I think a 5 amp fuse would be more appropriate for the circuit.

RazzMaTazz

Thanks again Ruley73!

Each of my two 3-port USB-power adapters supposedly can supply (2.1A+2.0A+1.0A=) 5.1A. So that's (2 x 5.1A=) 10.2A for both USB adapters -- though I kinda doubt that they could really supply that much amperage or that all of our devices would simultaneously demand that much. Still, I'd feel uneasy about anything less than a 10A fuse.

I wonder what the amperage rating is on the Equinox's power ports? Looking at the fuse box cover (diagrammed above), it's not clear to me which circuit they're on.

ruley73

I misread your previous post and underestimated the power needed by your setup. I thought you were only using one of the 3-port USB chargers and didn't realize that the Bluetooth adapter would be plugged into one of those ports. My estimate accounted for 10 watts x 3 USB ports plus 10 watts for the Bluetooth adapter for a total of 40 watts.

The amperage ratings on your USB adapters represent the output potential of each port and is rated at 5 volts (per the USB standard). Voltage directly affects amperage so 10.2A at 5 volts is not the same amount of power (wattage) as 10.2A at 12 volts (the voltage of your vehicles electrical system). You need to determine the peak amperage at 12 volts to correctly determine the fuse you should use. Your Bluetooth adapter will be plugged into one of the USB ports so it's power use is already accounted for in the 10.2A figure.

First, calculate the wattage: 10.2A x 5V = 51 watts
Then calculate the amperage at 12 volts: 51W ÷ 12V = 4.25A

Based on this you should be able to use a 5A fuse, but I think using a 10A fuse is acceptable.

The wiring diagram indicates that both power ports share the same 20A fuse located in the underhood fuse block (slot #3 - Auxiliary Power).

RazzMaTazz

Oops! Silly me. Your calculation is right. Doubling the voltage, halves the current. (... which is why power companies transmit power long distances at very high voltage). A 5A fuse should be adequate.

In fact, the that I installed had a fuse-holding plug-- which I cut off so that I could hard-wire it. I just checked that (in-plug) fuse and it's 5A. The port-splitter doesn't have very thick wiring so I'll swap in a 5A fuse.

It's good to know that the Nox's power ports are on the 20A fuse under the hood. I'll make a note of that. Thanks for looking into that.

And thanks again for all the advice in this thread!

Winnipegmike

Interesting reading. I thought I hit the jackpot when I found this thread. I want to do this exact same thing, but my equinox is a 2006, which has a different fuse panel. Does anyone know what fuse I can tap into on an 06?

RazzMaTazz

Hopefully somebody can give you a better answer but...

For my 2007 Equinox (as described above) I tapped into the sunroof fuse under the dash. But since the sunroof fuse seems to be located under the hood in the 2006, I'd probably try tapping into the power-window fuse with an Add-a-Circuit. (The power window fuse seems to be switched.) My aforementioned (power-port + USB-5V-adapter + Soundbot 360 Bluetooth receiver) solution still works perfectly after almost 8 years. However, nowadays 12V Bluetooth receivers are available, so I recommend that you add a 12V Bluetooth receiver like I recently on my 2008 Ford Edge...

For my 2008 Ford Edge (which has no Bluetooth but has an auxiliary audio input), I added a 12-volt "Bluetooth AUX Module 2 RCA Cable Adapter with Hands-Free Microphone 12V" for ~$16. It works just as well (arguably better) but it's much simpler to install because you don't need to use 5V USB adapters. For power, I connected the red/black power/ground wires of the Bluetooth receiver to the power/ground wires on the back of the radio (so that it turns on/off with the radio). I used a volt-meter to find the power/ground wires on the radio-harness. I connected some thin-stiff single-strand copper wires (that I had laying around) to the Bluetooth receiver's soft-braided wire, and then I jammed the stiff wires into the back of the wiring harness. But normal people would just splice into the power/ground wires with quick-splice connectors. I left the Bluetooth receiver behind the radio (out of sight) and I fished the microphone to the top of the steering column. You would also need to add a female-RCA-to-male-headphone-jack cable. If I were going to add Bluetooth to my 2007 Equinox now, I would add a 12V Bluetooth receiver. (You could also attach the 12V Bluetooth receiver's power/ground to a switched circuit, but then it would turn off with the ignition, rather than with the driver's door opening.)

Bluetooth AUX Module 2 RCA Cable Adapter with Hands-Free Microphone 12V:

RCA-headphone cable example:

Quick splice connectors:

Add-A-Circuit example: