I am looking to wire in my aux reverse lights so that I have the option of either having them come on when I throw the truck in reverse, OR when I flip a switch on the dash.. I am utterly clueless as to how to set this up. Can anyone direct me?

I know how to wire it all up without tying into the OEM reverse light circuit, it's how to tie in and make it work that has me stumped...

 

So you definitely want it to come on every time you go into reverse?

 

Either way, there are several write-ups on this thread:

https://www.f150online.com/forums/il...se-lights.html

 

Yes. If I didn't this would be real easy... Just run the same circuit design as I did for the front off road lights and call it good...

I would think the extra light while backing up should help in all sorts of situations...

 

Okay I think I found something...
http://www.sportsmobileforum.com/med..._Lights_Wiring



Does that look about right?

 

https://www.f150online.com/forums/il...hting-mod.html

 

Let me see if I understand the wiring on the relay... They seem to be standardized, with specific terminal numbers...

85 and 86 and the "coil" which appears to function as the trigger. The documentation I have seen doesn't say such, but all the diagrams show 86 has the + feed from whatever low amp signal source (Factory reverse circuit, switch circuit etc...), 30 is the common. which seems to be the target, although it looks from a couple of the diagrams that it could also be the higher amperage 12v source.

When power is NOT provided through the coil, 30 is closed to 87, but when power IS provided through the coil, then 30 is closed to 87a. Thus for example, if I tap into the OE backup lamp circuit and run it to 30, and 86 to ground, and run 12V power to terminal 30, then when the truck is not in reverse, terminal 87 gets power, but when the truck IS in reverse, terminal 87A gets power...

So if that is correct, then to advance the art as it were, from what I read in Patman's diagram and description, switched power for standalone use can be run to terminal 86 along with the signal wire from the reverse light circuit, diodes would be inserted inline on both the switched feed wire and the reverse light wire to keep them from backfeeding on each other.

So to complete this I would need...

1 relay, relay socket, and inline fuse holder. Like .

The lights in question are 18w each, so 18x2 is 36, and if I remember ohms law correctly watts / volts = amps, so I am looking at a total draw of 3 amps.

I suspect that there is some "fudge factor" to this lighting, and as such will probably run them off of a 5amp ATC fuse which I already have plenty of.

12awg primary wire in various colors. From what I understand of the 7 pin trailer wiring diagram the yellow wire in the center is the reverse light wire, so a spool of yellow for signal, a spool of red for power, a spool of black for ground, and spool of white for the connection to the lights.

I will need 12 gauge T taps to make the connection to the reverse circuit, 12 gauge ring connectors, solder, shrink wrap, split loom, and electrical tape, lots of that...

Do I have this right?

 

Sounds like you got it.

Most relays are 4 pin, and lack the 87A pin

The numbering is ISO standard, you will occasionally find relays with pins numbered as 1,2,3,4

 

dbhost: when you do this could you take some pictures and do a write up? I bought my truck with the 7 pin trailer already installed and want to add some reverse lights that come on in reverse and by the switch like yours.

 

greentitan,

That was my plan. If I can talk my lovely bride into handling camera duties for me while I work..

This will be multi part though. Part #1 is to install the 7 pin. This has been since day 1 my plan. I have not been able to take advantage of usage of a family owned TT yet due to the lack of the 7 pin plug... I have already looked at the install on that, and it is not that big or a project. Getting the lights done up right though, a bit more work. I have seen some nice installs, just not the way I am trying to get it done... I figure when it is all said and done, It should be a nice setup...

 

It is a nice setup and the exact same one I want to do. I've wanted to wire up additional things to my truck but I like following exact instructions before branching off on mine own. This was the first one that I'll be able to do that with, everyone else had similar ideas but it wasn't the way I wanted to do it. This will be a good first wiring project for me and give me some hands on experience to do more of them.

 

No problem. Most of my questions are due to rust on the brain... I USED to know this stuff before I changed careers, 20 years ago...

I guess I have just spent too dang much time virtualizing environments and worrying about backup schedules to keep automotive relay functions in the front of my brain...

I will try to get some video in this as well. Chances are better than good though that I will be posting it on my blog at http://daves-workshop.blogspot.com I will have Amazon links to each of the items required to perform the install of both the 7 pin harness, and the LED reverse lights to make it ultra easy for you to snag exactly what you need with no guesswork...

 

Want me to draw up a diagram to your specs?


Alltho the first one looks pretty similar to what you are wanting to achieve

 

I have the diagram more or less made. Where I am stuck is WTH is the value of the diodes I need? I can't seem to find the diagram that showed the diodes in the circuit...



Now for the bigger question. Diodes are typically surface mount pieces. How would I integrate a diode into an inline circuit?

 

what do you need diodes for?

what's going to backfeed?

alls you need is the reverse lights power wire to trigger the relay

if you go with your original diagram....



diodes are directional oneway gates letting the current only feed from one direction eliminating backfeeding situations usually wired inline without mounting on a surface.....

if you do need a diode usually a 2a or higher will work for 12v auto applications...