4 Pin to 7 Pin Conversion for trailer brakes?

[VAMike]

I have no knowledge of the Curt harness but would be leary of it if it ties into the tailight harness, especially if you have LED tailights. The problem is our trucks control and power the tailights through the BCM. They control and power the trailer lights through a separate TRM or with separate relays in the fuse box under the hood. The tailight control curcuits are not designed for the extra load of the trailer lights. Also the TRM module, if you have one, lets the truck know when a trailer is plugged in.

It's hard to tell from the pictures, but I think it's using the same connector the OEM one would, except the OEM also includes the connections for the bumper sensors and the 4 pin connector. So it's likely that the reason they're doing an inline is to leave the existing stuff alone and only add the 7 pin, rather than providing all the connectors and requiring rewiring everything in the bumper.

Sponsored

 

[Big Blue]

It's hard to tell from the pictures, but I think it's using the same connector the OEM one would, except the OEM also includes the connections for the bumper sensors and the 4 pin connector. So it's likely that the reason they're doing an inline is to leave the existing stuff alone and only add the 7 pin, rather than providing all the connectors and requiring rewiring everything in the bumper.

Just a caution. Our tricks with all the electronics don't like things plugged into curcuits that were not designed to handle the extra load. If it is plugged into the main body harness and using the curcuits designed for the trailer wiring, that's OK.

 

[muzicman0]

Just a caution. Our tricks with all the electronics don't like things plugged into curcuits that were not designed to handle the extra load. If it is plugged into the main body harness and using the curcuits designed for the trailer wiring, that's OK.

How would I know? It has a lot of positive reviews, but as we all know, that doesn't mean much.

Can I unplug the harness and check for voltage on the 4 pin connector?

 

[muzicman0]

I looked up the installation, and it says this:

Behind the rear driver-side axle along the frame rail, locate the black vehicle tow plug. The connectors will be similar to those on the custom connector. Separate the connectors taking care not to damage the locking tabs

That at least implies to me that it is the tow harness that it is connecting to the tow system, correct?

 

[Buckbull]

A 4 pin came on my Tremor. I swapped out the harness with no problem. Below is what i ordered.


https://www.tascaparts.com/oem-parts/ford-wire-harness-kb3z15k868d

https://www.tascaparts.com/oem-parts/ford-trailer-tow-harness-connector-fu5z14489a

 

[Big Blue]

I looked up the installation, and it says this:



That at least implies to me that it is the tow harness that it is connecting to the tow system, correct?

Sounds like it is connecting into the correct body harness and not the rear lighting. You should be good. Now hope you have the Trailer brake wires under the dash, some 2019s did not.

 

[muzicman0]

If not, I will use the Curt Echo. I did a VIN search and it listed the following:

Towing Equipment -inc: Trailer Sway Control
Trailer Wiring Harness
1770# Maximum Payload

So hopefully I will be good to go.

I don't care so much to make it look stock, so my plan is to mount it under the bumper with a bracket. I assume there is no issues with that.

I don't know if the maximum payload applies to the trailer. I thought it was 7500 lbs. Although my hitch is only class 3, so I think it is rated at 6,000 lbs.

 

[subquark]

I have a REDARC Liberty but haven't installed it yet. After much reading here and watching a zillion videos, it seemed like a good one for my light towing needs (light as in just a few times a year, but we'd like to get a travel trailer at some point).

I like the idea of the physical switch and possible placing it where the passenger could hit it in the case of an impending trailer sway situation (I don't want to see you guys posting videos of Soupie getting rolled by an out-of-control loaded down dump trailer! Oh the shame!). =D

However, since many peeps that are extremely well versed in towing are answering this post, I thought rather than starting a new post, I may find guidance here. And guidance can be gentle or a hard smack to the head (the latter is often needed). =p

I'd like to use an extender on my 7-pin to tap a backup alarm into. I was originally planning to do a relay off the Wolf Haus pigtail but it seems like I could directly tap the 7-pin's reverse signal. I'd prefer this to just directly tapping the existing harness wire.

I haven't crawled under the back to look at this, but would this extension fit? Thanks!

https://www.amazon.com/gp/product/B08WL7L5JQ

 

[mtbikernate]

I don't know if the maximum payload applies to the trailer. I thought it was 7500 lbs. Although my hitch is only class 3, so I think it is rated at 6,000 lbs.

Your vehicle can only safely tow as much as the lowest-rated component in the system. If your receiver is rated to 6,000lbs, then your max tow can only ever be 6,000lbs. If you use a ball mount rated to 1500lbs, then your system rating is only going to be 1500lbs. If you use a ball mount rated to 10,000lbs, your max tow can only be 6,000lbs.

I see a lot of people misunderstand towing ratings in the general public. The common one I see is that they think that if the rating of the receiver is higher than the vehicle's mfr towing ratings, that they can then load the hitch higher than the manufacturer's stated rating.

For example, more than once in the mountain bike community, people have told me that because they installed a hitch receiver with a 300/3000lb rating on their car (has a 150/1500lb max rating), that they can load up a bike rack to 300lbs. Also failing to understand that bike racks that stick out far from the rear of the vehicle effectively act like hitch extenders, and the general rule you see oft-quoted is that hitch extenders reduce tongue weight capacity by 50%. This is one reason why you see so many small cars carrying lots of bikes squatting badly.

 

[muzicman0]

Your vehicle can only safely tow as much as the lowest-rated component in the system. If your receiver is rated to 6,000lbs, then your max tow can only ever be 6,000lbs. If you use a ball mount rated to 1500lbs, then your system rating is only going to be 1500lbs. If you use a ball mount rated to 10,000lbs, your max tow can only be 6,000lbs.

I see a lot of people misunderstand towing ratings in the general public. The common one I see is that they think that if the rating of the receiver is higher than the vehicle's mfr towing ratings, that they can then load the hitch higher than the manufacturer's stated rating.

For example, more than once in the mountain bike community, people have told me that because they installed a hitch receiver with a 300/3000lb rating on their car (has a 150/1500lb max rating), that they can load up a bike rack to 300lbs. Also failing to understand that bike racks that stick out far from the rear of the vehicle effectively act like hitch extenders, and the general rule you see oft-quoted is that hitch extenders reduce tongue weight capacity by 50%. This is one reason why you see so many small cars carrying lots of bikes squatting badly.

I understand that. Makes perfect sense. My point was the truck has 7500 lbs towing, my hitch is 6000 lbs, so I assume 6000 lbs towing (assuming all other parts are rated at that or higher).

The question was what is the " 1770# Maximum Payload " in the VIN decode referring to. Is that tongue weight or something else?

[EDIT] It looks like the 1,770 lbs payload is the cab and bed based on a quick google search. So it has nothing to do with towing.

 

[subquark]

I understand that. Makes perfect sense. My point was the truck has 7500 lbs towing, my hitch is 6000 lbs, so I assume 6000 lbs towing (assuming all other parts are rated at that or higher).

The question was what is the " 1770# Maximum Payload " in the VIN decode referring to. Is that tongue weight or something else?

[EDIT] It looks like the 1,770 lbs payload is the cab and bed based on a quick google search. So it has nothing to do with towing.

Yep, I think you're mostly correct.

However, I believe tongue weight is part of that payload number.

My fat @$$, plus all the crap this forum forced me to buy, plus 100 pound tongue weight = overloaded! (but that fixes our poorly engineered bed rake)

perfect bed rake, makes unloading crap easier! =p

 

[Grumpaw]

I understand that. Makes perfect sense. My point was the truck has 7500 lbs towing, my hitch is 6000 lbs, so I assume 6000 lbs towing (assuming all other parts are rated at that or higher).

The question was what is the " 1770# Maximum Payload " in the VIN decode referring to. Is that tongue weight or something else?

[EDIT] It looks like the 1,770 lbs payload is the cab and bed based on a quick google search. So it has nothing to do with towing.

As posted, the pay load is the rated capacity of the entire load the truck can be "loaded with", including all occupants.
And the tongue weight is counted as payload....a 600 lb tongue weight is counted just as if you placed 600 lbs of "stuff" in the bed.

 

[Big Blue]

Since you bring up the payload question. The allowable payload for your truck is on the sticker on the driver side door jam, and is for the truck as it came from the factory. Any modifications you do, including that new hitch you just added, reduce that number.

I know this whole thing of what counts as what can get real confusing. And when you add towing into the mix, it gets worse. When you are towing nearax like @Grumpaw it will make your head hurt.

 

[muzicman0]

Yep. Makes sense. The tongue weight of the trailer will probably be sub 200 lbs. Loaded it will most likely be less than 250, so while good to know the info, I don't think I will have any issues.

 

[mtbikernate]

perfect bed rake, makes unloading crap easier! =p

pssshhhh, I've seen much worse

Sponsored