Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register
  • Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
  • The final cut of TMC Podcast #27 is available now with topics time-stamped. We discussed: Consolidation in LiDAR manufacturers; Volvo EX90 shipping with LiDAR; FSD Beta Full Release in N.A.; FSD detecting autopilot cheats, Gwen Shotwell directly overseeing SpaceX Starship; and more. You can watch it now on YouTube. We should have it published to podcast networks shortly.

Switched 12v power line to tap into?

Hi,

I'm installing a built in radar detector to my Model S and am looking to tap the equivalent of switched (ignition on) power in the cabin. Has anyone done something similar? I don't want to do an always-on tap in case my RD doesn't auto-shut-off after inactivity. Any suggestions appreciated.

Thanks
 

Lloyd

Well-Known Member
Supporting Member
Jan 12, 2011
6,405
2,339
San Luis Obispo, CA
Hi,

I'm installing a built in radar detector to my Model S and am looking to tap the equivalent of switched (ignition on) power in the cabin. Has anyone done something similar? I don't want to do an always-on tap in case my RD doesn't auto-shut-off after inactivity. Any suggestions appreciated.

Thanks

I used the Power steering 5 amp fuse for mine. It comes on when the car is turned on.
 

Lloyd

Well-Known Member
Supporting Member
Jan 12, 2011
6,405
2,339
San Luis Obispo, CA
Thanks for this, is it easy to get the wire from the frunk (where the fuse box is) into the cabin?

I went through the gromet where the power for the Heater is routed in front of the passenger seat just towards the middle from the cabin air intake (also posted in 9500 ci thread) . There are two orange wires about #8's going through a large gromet. I made a small hole lateral to those wires for my power and sensor wires to pass through the firewall. Silicone to seal afterwards.
 
I went through the gromet where the power for the Heater is routed in front of the passenger seat just towards the middle from the cabin air intake (also posted in 9500 ci thread) . There are two orange wires about #8's going through a large gromet. I made a small hole lateral to those wires for my power and sensor wires to pass through the firewall. Silicone to seal afterwards.

Funny to read 'firewall' in this context. Did you use high-temp sealant, too? :smile: I don't know what you'd call it other than that, though.
 
  • Funny
Reactions: CalBlue 85D
I went through the gromet where the power for the Heater is routed in front of the passenger seat just towards the middle from the cabin air intake (also posted in 9500 ci thread) . There are two orange wires about #8's going through a large gromet. I made a small hole lateral to those wires for my power and sensor wires to pass through the firewall. Silicone to seal afterwards.

Thanks. I looked thought the 9500ci thread and was wondering if you have photos of the power wire entering the cabin as well (or did I miss them) or on the other side in the frunk entering the fuse area? I just hardwiring a 9500xi up near the rearview mirror ...

I am sure it will all be more clear once I have the car in hand next week.

Thanks,
 
Thanks. I looked thought the 9500ci thread and was wondering if you have photos of the power wire entering the cabin as well (or did I miss them) or on the other side in the frunk entering the fuse area? I just hardwiring a 9500xi up near the rearview mirror ...

I am sure it will all be more clear once I have the car in hand next week.

Thanks,

I actually made a hole through the "firewall" just to the left of the drain hose you will see when you take the frunk apart. Worked well since I needed to pass so many wires through for the laser detectors and radar unit.

For power, I used the glove box light fuse. I like to keep it powered since it saves the noise and delay of waiting for boot-up.

Note that the coating on the windshield will significantly impact a detector put in the window - hence why so many are doing custom installs.

Aaron
 

Lloyd

Well-Known Member
Supporting Member
Jan 12, 2011
6,405
2,339
San Luis Obispo, CA
I went through the gromet where the power for the Heater is routed in front of the passenger seat just towards the middle from the cabin air intake (also posted in 9500 ci thread) . There are two orange wires about #8's going through a large gromet. I made a small hole lateral to those wires for my power and sensor wires to pass through the firewall. Silicone to seal afterwards.

I did not take photos. It will be readily visible if you follow my directions above.
 
Just got done installing my Power Magic Pro (Battery Discharge Prevention Device) to support the install of my BlackVue DR650GW HD 2 Channel Dash Camera. I was extremely uncomfortable following the directions that directed us to go through the passenger side firewall (right next to the DC to DC 400 VDC 85KW Inverter that feeds the Low Power DC Battery 12VDC.

Here is the option I chose:

1. Remove the rear funk cover parallel to the windshield.
2. Zip tie the Power Magic Pro near in between fuse Panel #2 and fuse panel #3 (see picture)
3. Jack the car up and remove passenger side wheel and wheel well liner (5 quick disconnects and one 12 MM bolt)
4. Move wheel well liner out of the way
5. find the conduit that run the long axis of the car parallel to the High Power Battery (see picture)
Model S Passenger side wheel well.png
Model S Passenger side conduit.png

6. Remove passenger side skid plate and drill one hole through skid plate 2 inches back from the door hinge.
Model S Passenger side door sill.jpg

7. Fish a coat hanger down the conduit to connect to the wire that has been fed into the passenger side wheel well.
8. Pull coat hanger back with wire connected - you are now in the passenger compartment and have worked your way around the firewall.
9. Connect the accessory wire "Trigger" to #F75 (Power Steering) in fuse box 3 and connect constant "battery" wire to #F54 (Open) in fuse box #2.
Model S Fuse Box.png

10. Connect ground wire to location in picture.


Hard part is over - reassemble and test for power.
 

Attachments

  • Model S Passenger side conduit.jpg
    Model S Passenger side conduit.jpg
    1.7 MB · Views: 875
  • Model S Passenger side wheel well.jpg
    Model S Passenger side wheel well.jpg
    1.6 MB · Views: 863
Last edited:

HankLloydRight

No Roads
Supporting Member
Jan 18, 2014
13,545
11,985
Connecticut
See attached images.

Step 1: Remove trim panel #1 (blurry pic, sorry). You can use your fingers or a pry tool. It just snaps off in one piece.
Step 2: Remove trim panel #2 (clear pic). It also just snaps out. You may need to remove the floor mat to get it out.
Step 3: Pull back carpet in the corner (last three pics) to reveal the connectors. They might be further down/back the first time, but they should be there.

You can see one connector in the pic, but there are actually two down there. There is a little slack in the wire, so you can pull them out to get to the leads going into the connectors. I used a wire tap to tap into the existing wires. Use a voltmeter to figure out which one is positive and negative (or just use any other ground for negative).

I used this tap to install both a rear-view mirror mounted dashcam as well as a Valentine 1, including the concealed display and remote audio adapter. I did add a 5 amp inline fuse on the positive tap just for extra protection.

I've since pulled out the V1 and had a Bell STiR+ professionally installed, and they also used this same tap location for power. I also ditched the mirror mounted dashcam and installed a LUKAS 5900 duo connected to constant +12v via the OBDII connector in the driver's footwell. That's also very easy to do for constant power not needing to tap the fuse box or run wires from the frunk or through the firewall.
 

Attachments

  • IMG_3290 (Small).JPG
    IMG_3290 (Small).JPG
    58.1 KB · Views: 854
  • IMG_3293 (Small).JPG
    IMG_3293 (Small).JPG
    112.4 KB · Views: 870
  • IMG_3297 (Small).JPG
    IMG_3297 (Small).JPG
    79.9 KB · Views: 836
  • IMG_3303 (Small).JPG
    IMG_3303 (Small).JPG
    60.1 KB · Views: 868
  • IMG_3304 (Small).JPG
    IMG_3304 (Small).JPG
    45.7 KB · Views: 856

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top