Wiring Connections

[Butsky]

We have an original ( I think) wiring plug on our Boler( no brakes) which is a female end, 7-pin spade connector, the center post not being used. There are black and red wires that aren't in our flat 4 pin tow vehicle. Since our dome lights are inoperable with 110 plugged in, I figure the red is perhaps a power source for them only when attached to tow vehicle. What would the black wire be, power as well, as perhaps for the 3-way fridge? I want to trash the big 7 pin connector and solder up a 4 pin flat style connector. My flat has the traditional green/yellow/brown/white wires. Should I solder the red and or black to the brown power wire! I don't want to pop anything with a short. I want to tread carefully on this one...

[Butsky]

Here is a pic of the wires.

[steve dunham]

Red = Left turn / brakes
Green = Running lights
Black = 12 VDC + Pos
( Battery charge line)
Brown = Right turn / brakes
Yellow = Backup / auxiliary
White = 12 VDC - Neg - Grd
Blue = Trailer Brakes

Using only a 4 wire plug would not provide for trailer brakes or charging the trailer battery when hooked up to your tow vehicle

[floyd]

this might help some....

[Glenn Baglo]

I would rewire the tow vehicle for 7-pin rather than the trailer for 4-pin.

[John in Michigan]

My former 1974 Boler 13 had original wiring with colors listed by Steve Dunham. (I converted the camper from 4-pin to 7-blade and added brakes.)

To answer the OP's question, the Boler 13 dome lights get 12vdc power from the battery or ac/dc converter. And the wire colors between the dome lights and the battery or ac/dc converter are black (+) and white (-).

You might notice that the wire colors used in your tow vehicle are DIFFERENT than the wire colors used in your 40 year old Boler 13. In the Boler 13:

Red = Left turn / brakes
Green = Running lights (and tail lights)
Brown = Right turn / brakes
White = 12 VDC - Neg - Grd

HOWEVER for your flat four connector the wire colors are mapped as:

1. white = ground
2. brown = running lights and tail lights
3. yellow = left turn / brakes
4. green = right turn / brakes

Presumably your vehicle wires match the latter wire color scheme, but you will have to verify.

[mary and bob]

It appears that the OP's trailer does not have a battery or power converter ??

[John in Michigan]

As you say, definitely tread carefully. On my 1974 Boler 13, there was a flat 4 connector and tracing these 4 wires back to tail lights and side marker lights, I determined:

Red = Left turn / brakes
Green = Running lights (and tail lights)
Brown = Right turn / brakes
White = 12 VDC - Neg - Grd

There was also a yellow wire dangling near the two tail lights (not connected), and I determined this was an unused wire intended for backup lights.

[John in Michigan]

Coincidentally, my Boler 13 had no battery or converter, just 2 dome lights with with disconnected black/white wires. I added a converter and wired in dome lights.

[Butsky]

It is true, I have no battery or converter on board to run dome lights, fridge or any other 12 volt requirement. I believe that the way this Boler came, it would have to be hooked up to tow vehicle to be powered up for 12V. When detached from tow, I have to have 110V for any lighting (fluorescent). Boon docking, I would use flashlights. Would perhaps like using the fridge for a long road trip and use tow power to run the three way fridge or use the propane.

[floyd]

how about this it does both 7 and 4 way trailer plugs...

https://www.amazon.com/Hopkins-Towin...er+Plug+Wiring

[Byron Kinnaman]

Originally Posted by steve dunham

Red = Left turn / brakes
Green = Running lights
Black = 12 VDC + Pos
( Battery charge line)
Brown = Right turn / brakes
Yellow = Backup / auxiliary
White = 12 VDC - Neg - Grd
Blue = Trailer Brakes

Using only a 4 wire plug would not provide for trailer brakes or charging the trailer battery when hooked up to your tow vehicle

My guess is that in most places you would tow that trailer brakes would be required. In some States if there's brakes on the trailer they have to be functional.

[steve dunham]

Speaking for myself only , I would not tow a 2000 or 3000 lb travel trailer without functioning brakes especially at highway speeds or in the mountains.
My utility trailer which I use only for hauling firewood does not have brakes but is only used on back country roads at 25 mph or less. I had to make one panic stop with a full load of oak to avoid hitting a deer . Once was enough to convince me of the necessity of good trailer brakes !.

As Donna D has pointed out several times , trailer brakes are much cheaper to replace than vehicle brakes.

[Darral T.]

This is the one I installed on my truck. I was able to plug my existing 4-pin into this Hopkins connector and not have to rewire. Works great!

Originally Posted by floyd

how about this it does both 7 and 4 way trailer plugs...

https://www.amazon.com/Hopkins-Towin...er+Plug+Wiring

[Borrego Dave]

Originally Posted by Darral T.

This is the one I installed on my truck. I was able to plug my existing 4-pin into this Hopkins connector and not have to rewire. Works great!

I must be in hog heaven, I've got the flat 4, round 6 and big 7 all on the same tug .

[Gerry]

Originally Posted by floyd

how about this it does both 7 and 4 way trailer plugs...

https://www.amazon.com/Hopkins-Towin...er+Plug+Wiring

Also available is a converter plug from a 7 wire down to a 4 wire plug in that I use when hauling my small utility trailer.

[Darral T.]

I've never even used my "4" in the 7 yrs of hook up. You must pull alot of hogs!

Originally Posted by Borrego Dave

I must be in hog heaven, I've got the flat 4, round 6 and big 7 all on the same tug .

[floyd]

Originally Posted by Darral T.

I've never even used my "4" in the 7 yrs of hook up. You must pull alot of hogs!

One nice use for having both 7&4 is using the 4 plug side an extra set of lights in addition to tow dolly lights or iffy taillights on a project trailer.

[Darral T.]

Ahhh... you brought back to memory one thing I DID use my 4 for...and that was hooking up my backup camera when I had it temporarily on the tailgate.

Originally Posted by floyd

One nice use for having both 7&4 is using the 4 plug side an extra set of lights in addition to tow dolly lights or iffy taillights on a project trailer.