I need a relay or something

[zogthegreat]

Hi everyone!

I have a bike rack on my 2011 Ford Taurus that I want to install a light that activates when I step on the brakes. Due to the way Ford setup the lights on the Taurus, I can't just tap into the brake lights in the rear. I did manage to tap into the brake light that is in the back window, but due to voltage drop, I'm only getting 6v at the end of the wire. Since I already have a 12v hot wire running to my trailer wiring, what I would like to do is have the wire that comes from the rear window brake light run to some kind of relay or switch to the 12v hot and then from the 12v hot to the bike rack.

Does anyone have any suggestions?

Thanks!

zog

 

[duke37]

Just use a mosfet with the gate driven by the brake signal. It should have a capability of 10A or so.
The gate should be connected via a resistor, say 10k to 100k and a pair of diodes to restrict the gate to between 0V and 12V.

 

[CDRIVE]

While I really don't understand why you're getting a 6V voltage drop at the hatch light I believe you're asking for this...

Chris

 

[Herschel Peeler]

Hi everyone!

I have a bike rack on my 2011 Ford Taurus that I want to install a light that activates when I step on the brakes. Due to the way Ford setup the lights on the Taurus, I can't just tap into the brake lights in the rear. I did manage to tap into the brake light that is in the back window, but due to voltage drop, I'm only getting 6v at the end of the wire. Since I already have a 12v hot wire running to my trailer wiring, what I would like to do is have the wire that comes from the rear window brake light run to some kind of relay or switch to the 12v hot and then from the 12v hot to the bike rack.

Does anyone have any suggestions?

Thanks!

zog

You gave a trailer wiring without a brake light going through it?

 

[CDRIVE]

Here's another version that includes a Gate Zener. It can be a Zener voltage of 9V - 12V. It will absorb both positive and negative spikes.

Chris

 

[CDRIVE]

You gave a trailer wiring without a brake light going through it?

Ha, I didn't catch that. It doesn't make any sense. Does it?

Chris