relays where are they?

[fastford]

Where do I find the light relays if I have them in my truck? I've got four relays unde the hood with space for another thats been left empty. Every thing is so messed up I want to start fresh and send a dedicated voltage to the required lights. 7 way system. The only two wires that are in thier proper place is the brake(blue)and ground(white). The other five do not operate the lights properly when conected to their proper positions on the plug. However if I splice off the wires that actually go to the tail lights I can make it work. You are reading right I have a set of wires for the trailer or I can splice off the taillight wires.
Also is the orange or the black for battery power?
thanks

[STurbo90]

There should only be 4 relays in the underhood box, no 5 is for factory fog lights(lighting model).

relay #4 is for the trailer marker lamps.

also in the underhood box,

fuse 4 (25amp) is for the trailer running lamps.
fuse 6&7(10 amp) are for trailer right and left hand stop/turn lamps.
fuse 18 (30 amp) is for trailer charge wire.
fuse 21 (30 amp) is for trailer brake feed.



When you say that only 2 wires are in their proper place,

do you mean that the wires were physically removed?
or cut somewhere between the front and back?
or they simply do not supply voltage?

The trucks tail lamps are fed from the same source, but they are separately fused, so it is not ideal to add any more lights to what is already there.

At the rear 7 way plug, the wires should be,

Yellow Left turn
Green Right turn
Blk/Grn backup lamps
orange Battery charge
Brn/wht Marker lamps
Blue Trailer brakes



In the separate relay box attached to the side of the underhood distribution box should be two relays.

one for the trailer backup lamps, and the other for the trailer charge wire.

[fastford]

What I ment to say is that only the brake (blue) and ground(white) work properly in their called for positions on the 7 way plug. The other 5 colors do not work properly in thier positions designated by the plug. With a test light I figured out what each color should be and wired them into the proper plug position. I could get no test light indication off the orange or black wires or continuity with the meter to ground off them either.
When plugged into the trailer I found I had one bright tail light and one dim one. During signal operation I found my marker lights flashing as well. A neet effect but not desired.
This is why I was thinking of going relays. Using the existing lights on the truck to actuate the relay and feed the trailer with a seperate dedicated power supply. Therby bypassing the existing mess while not putting any excess load on the truck wiring.
Any thoughts?

[STurbo90]

I still don't understand what you mean when you say in their proper positions, the wires output is not dependent on its position.

The wires were just hanging and you had to reattach them to the 7 way plug?


Were you testing those with the key on and in reverse?
The charge relay is only active with the key on, and the reverse, well,

Both the Orange charge wire, and Black back-up lamps, will not show continuity to ground, they both are switched by a relay, so when they are not active and the relay is open the wire is broken from the circuit.


Were any of the fuses I listed blown?
So the test light functions normally with turn/stop and brake?

It sounds like somthing is wrong with the trailer itself.

I don't think it is necessary to add relays for the turn signals, unless you have a lot of trailer lights.

[fastford]

Ok hear is what I see, along with the normal lights for the truck lights I have two bundles of wire seperated from each other one contains blue,orange and black, the other contains yellow brown,wht to ground and green.
When I tested it out with the test light I found
1 white to white
2 blue to blue
3 green to brown
4 black to orange (guess)
5 red to yellow
6 brown to green
7 aux left emtey but was going to put black in it
The first color is what it should be the second is what works.

Now looking at the piece of cardboard that the plug came with it says
1 white grd
2 blue brakes
3 green lights terminal 3 a 1 filament bulb
4 black battery charge terminal 4
5 red stop and left turn term. 5
6 brown stop right turn term. 6
7 yellow aux ground or aux circuit to term 7

So obviously the colors on the plug cant be trusted all I need to find now are the proper homes for brown (tail lights) And Black (back up).
Possibly swapping the green and ground terinals may fix the problem of flashing markers.
Logic works way better when you can see it in front of you.
As for your questions ALL fuses are good. However there are no relays located outside the power distribution box which would explain no reverse lights or battery charge.
This whole saga started with me wanting to install back up lights for a fall trip.

[fastford]

green and Brown terminals

[STurbo90]

Okay, now I see you have an aftermarket 7 way plug that you are trying to hookup to the factory wires.


Yes, those wires do not seem to match exactly.

According to your description,

cardboard wires=Truck wires:

1. White(grd)= white
2. blue(Brakes)= Blue
3. green (tail)= Brown/White
4. black(12v+)= Orange
5. red(left turn)= Yellow
6. brown (right turn)= Green
7. Yellow(aux)= Black/Lt Green


Yes, the two relay sockets outside of and next to the underhood distribution fuse box need relays in them for the backup and charge wires to work.