Wiring Issue?

[dennis b]

Hey everyone. I have a 2005 Fi50 and need to wire up the third brake lite on my cap. Was going to pop off tail lite assembly and tie into it. But was told not to do it there because brake and turn sig run on same wire and third brake lite would flash when using signal. If this is true how would I wire this up?

[Jmooney]

[dennis b]

So you sayin to wire into 7 way harness?

[dennis b]

Originally Posted by dennis b

So you sayin to wire into 7 way harness?

[Murff]

Originally Posted by dennis b

X2 ???

Murff

[Jmooney]

Never mind, you would get the same result

[North of 49°]

Some pickups have an additional wire for the center high-mount brake light, running along the driver's side frame rail, near the back. My old '00 GMC Sonoma had one which I didn't know about, so when I installed the cap, I just spliced a wire for the cap's brake light into the existing brake light at the top of the cab. Then I found out about that dedicated wire and it made things a lot easier. Might be worth taking a look.

[blderman]

Originally Posted by dennis b

Hey everyone. I have a 2005 Fi50 and need to wire up the third brake lite on my cap. Was going to pop off tail lite assembly and tie into it. But was told not to do it there because brake and turn sig run on same wire and third brake lite would flash when using signal. If this is true how would I wire this up?

There should be a 3rd cab light wire already in place by the trailer wiring harness. Every truck I have owned has had this wire.

[Jmooney]

They sell third brake light units that attach to your tow hitch receiver. Wonder how they pick up brake signal power using those things. I would have guessed they they just plug into your tow feed

[blderman]

Originally Posted by Jmooney

They sell third brake light units that attach to your tow hitch receiver. Wonder how they pick up brake signal power using those things. I would have guessed they they just plug into your tow feed



Attachment 17893

They work because there isn't a ground. As long as the light doesn't have a path to ground it wont't blink.

[SouthCo]

I had a Tacoma many years ago and when I had a cap installed, they tied it into the drivers side rear taillight. Not saying that is the right way or best way but I never had any problems with it.

[Seann45]

The proper way to do it is to run a wire from the brake pedal switch to the 3rd light. IF you tie into your tail lights the third will blink when you put on the signal light for the side you tied into.