Adding a second camera / CMU isolator

I received an email from Nikos P. this morning asking:

hello my friend i need to enable back camera rotate i place a cam and its not turn back when i put reverse

I’m not sure I understood his question, but it sounded like he added a second camera without a video switcher, so it took priority over the reverse camera.  I remembered coming across a solution months ago that was developed for our Infotainment Systems by a small company in Russia (with which I have no affiliation with, other than sending them an email asking if this would work on the MX-5 and the 124 Spider – it apparently does, as they’ve been added to the list of intended vehicles) which allows you to control the various camera functions using the DSC switch (or an independent switch if you prefer).

It appears that their various electronic products (Wireless screen mirroring, DVD and TV controllers, etc) are well thought-out and fabricated nicely, using wiring connectors that mate with the appropriate OEM connectors in the vehicle to minimize splicing, and the Front View Camera Controller seems like it is fairly priced at $110, which includes shipping.  I am presenting this, to hopefully answer Nikos’ question; in case others might also find it helpful; or in case others might wish to purchase this solution for even greater utilization of the 7″ screen.

Front View Camera Controller v 52D.11

If your car has a rear-view camera installed, then by adding a controller, it will make it possible to also install and view the output of a front view camera as well

ACTIVATION:  The choice of modes is possible by pressing and holding the “DSC” button for more than 1 second. Each press switches the OFF – AUTO – ON
(it seems that more recently, this was changed to short pressing the “INFO” button on the steering wheel instead)

  • OFF.  (front view camera disabled)
  • AUTOMATIC.  When the vehicle is moving forward at a speed of no more than 7 km / h, the image from the front view camera is displayed.
  • ON.  In this mode, the image from the front view camera is constantly displayed.


Instructions for installation and implementation (includes wiring diagram).

CMU ~ Isolator

[Added 6/21/2018]

Chances are very good that the isolator that slides onto the tab at the rear of the CMU will detach itself while sliding the CMU out of the DIN slot.  Just be aware of this as you are assembling the CMU back into position.

CMU isolator2

courtesy of anderml

CMU isolator3

courtesy of poniliu

CMU isolator1

courtesy of anderml

8 thoughts on “Adding a second camera / CMU isolator

  1. Apparently Nikos’s issue was wiring up an aftermarket “universal cam” to a Mazda (since all Spiders already have a camera) incorrectly, such that the camera image didn’t appear when putting his car into reverse. Hopefully the wiring diagram in the instructions will help him out.


  2. Okay. I have thick moments, and this is one of them. Assuming you’re not being shot at and trying to drive a car with your head below the dash, why would someone want a front view camera displayed on the infotainment screen? I get the value behind a dashcam for use in insurance or accident claims, but the infotainment system doesn’t record video (does it?). Confused… again… lol


    • Cal, I agree and although I won’t be taking this project on, I found it interesting nevertheless. I guess it might be mainly for parking purposes for those without the optional parking sensors, so that you can avoid hitting parking blocks, curbs, and other potentially disastrous obstructions, especially with a lowered car. It could also be an alternate means of monitoring a hidden grille cam used in place of a dash cam. The camera itself would have to have continuous recording capability with a built-in memory card slot to serve as an accident recorder.


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