Cheaper alternative to expensive 4th brake lights.

[ponie1992]

If I went with the knock off this is what I would try.

That would work, no problem.

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[doulos4jc]

That would work, no problem.

How much of a pain would it be to get to it? May be more trouble than it's worth...dunno.

 

[ponie1992]

How much of a pain would it be to get to it? May be more trouble than it's worth...dunno.

That, I don't know. That's why I'm not going that route.

 

[ob1]

Since the convertible uses the truck lid for the 4th brake light wouldn't that be in the wiring bundle in the trunk some where.
I would think that Ford uses the same main wire bundle for both body styles and just connects a wire harness when a convertible is built?

 

[ponie1992]

Since the convertible uses the truck lid for the 4th brake light wouldn't that be in the wiring bundle in the trunk some where.
I would think that Ford uses the same main wire bundle for both body styles and just connects a wire harness when a convertible is built?

Good question, but without wiring diagrams I have no idea.

 

[ob1]

Found this in DIY.
http://www.mustang6g.com/forums/showthread.php?t=33445&highlight=wiring+diagram

 

[ponie1992]

Found this in DIY.
http://www.mustang6g.com/forums/showthread.php?t=33445&highlight=wiring+diagram

Thanks!

 

[ponie1992]

After thinking about this some more today, I can accomplish how I want this to work with one relay. It will still work as I stated before: normal braking, the 4th light will be on and solid. Left turn, right turn or hazards, the 4th light will flash.

 

[Diode Dynamics]

After thinking about this some more today, I can accomplish how I want this to work with one relay. It will still work as I stated before: normal braking, the 4th light will be on and solid. Left turn, right turn or hazards, the 4th light will flash.

I think you'd just want to use a few diodes. Run a wire to each of the "inboard" (#1) signals, run each one through a diode so they don't light each other up, then connect both of those to the bulb wire. Still going to light up with turn signal, but if you're fine with that look, a few diodes will definitely make it work that way.

 

[ponie1992]

I think you'd just want to use a few diodes. Run a wire to each of the "inboard" (#1) signals, run each one through a diode so they don't light each other up, then connect both of those to the bulb wire. Still not a fan of the center light illuminating with turn signals when the brake's off, but that will definitely make it work that way. [emoji106]

Could do it that way, but I already have relays laying around. No diodes handy. But, thanks for offering the idea![emoji106]

 

[ob1]

Let us know what the wire coloring is for the other side please.
Thanks for your help with this setup!

 

[ponie1992]

Got the relay installed today and now the 4th light flashes with the right signal as well. I discovered yet another flaw in my setup. When the left signal is on and braking, the 4th light will remain steady on due to the right light providing power to the relay to change the state of the contacts. Right turn and braking, the 4th light will flash. I may just have to go the diode route. Anyway, here is a pic of the relay.

 

[doulos4jc]

The $80 on the DD unit might be a fair price after all...just for the plug and play factor alone.

 

[ponie1992]

I never said it wasn't worth it. Just trying to make it work on my own and cheaper. The plug and play of the DD is worth the cost, I'm sure.

 

[doulos4jc]

I never said it wasn't worth it.

Yea, I know. Others did.

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