[ETBill]

I have a US 2012 Elantra Touring, auto trans, 2.0 gas engine, factory cruise control with buttons on steering wheel and indicators on dash.

In May '21 I had an issue where the high mounted LED brake light worked, but the side mounted brakes lights did not come on.  At the same time the cruise control stopped setting reliably, and then would not set at all.

I "fixed" (not fixed correctly, but got the car back on the road safely) the brake light issue by adding wire jumpers from the LED brake light to the side brake lights:  Stop brake lights do not work high mount stop light does- any solution to this?

At that time I installed an Auto Zone brake light switch.

The cruise control does not set.  I disconnected the replacement Auto Zone brake switch, an connected a factory brake switch, 93810-3KR0CQQH which I believe is the correct part for my car.  With the brake switch hanging in free air, the high mounted 3rd brake light glows dimly all the time (with brake plunger pushed in, or relaxed).

Is it possible that the 3rd high mount brake light glowing dim indicates there is voltage back feeding the switch? Is there another factory brake switch part number that might have a built in resistor to take care of this issue?

Thanks in advance for taking a look at this post and adding your thoughts.  Please understand that my adding wire jumpers to the brake lights, and throwing brake light switches at the car in hopes of finding the combination that will make the cruise control work, is not laziness or not respecting the car enough to fix it the right way.  My daughter takes the car to university, so I have limited time when she visits.  The priorities are make it safe, and get it back on the road quickly so she can go back to school.  Fixing it right will likely have to wait for now.

Thanks! ETBill

[Aye30]

Hi, from what I have learned,reading this forum, the factory brake switch has two separate circuits. One normally closed and the other normally opened. I believe that the failure to set cruise control, was due to the switch not reporting back it was in the undepressed position, i.e pushing the pedal dissengages the CC. It may be related that the center stop light runs off of the normally open circuit and the lower stop lights run off  of the normally closed side of the switch. And by bridging them weird things may happen.  I would remove any wiring you have added to the circuit, and ensure the correct position of the factory switch, as if it is installed too high or low it will not allow the cruise control to work as the company designed it to.

[The Gonz]

I can't verify Aye's logic 100% other than to agree that reversing what you did and seeing whether that makes a difference is a very sensible step towards resolving this.