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Trailer hook up questions with a blue, wide electrical connector

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Old Aug 22, 2020 | 10:16 PM
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Default Trailer hook up questions with a blue, wide electrical connector

I have some furniture to pick up across town. Unfortunately it won't fit in the back of my 2-door Blazer, so I plan to rent a UHaul trailer to haul it.
My Blazer isn't already equipped to tow, so I have several questions about getting started.

The bumper surface plastic says "remove for access to trailer ball". Does the whole plastic piece pop off, or does it expect me to cut into it? For a simple, light job, that's all I need. I don't plan to do any serious towing except for transporting furniture like sofas, dinning tables, wardrobes, etc... and it's not frequent. Just for moving stuff around.

Also I'm confused about the wiring. A lot of images and products I looked at show a 4 pin plug, or this cylindrical plug with 7 contact points in it. I don't seem to already have that, so am I going to need a kit to splice into the existing wiring?

I have have these two wire harnesses trailing off the wire harness coming down the driver-side frame.

What does this wide plug go to? I can't seem to find anything related to trailer lights that would fit it.



And this one has no plug on it. It's just a deadend wire that's been taped over from the factory.
There's a sticker on it that says "disconnect battery before remove tape from wire"


 
Old Aug 22, 2020 | 11:11 PM
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You don't list the year of your truck so I cant be certain of your wiring but in a 2002, there is a 4 wire fused provisional wiring harness for trailer lights provided by the factory that runs to the back of the truck underneath and is tucked up near the spare tire. This harness wires need to be connected to a receptacle like:

https://www.etrailer.com/Wiring/Tow-Ready/30717.html

And then you need this adapter to translate from your new 7 pin socket to the std 4 pin uhaul harness:

https://www.etrailer.com/Wiring/Hopkins/47345.html

Then you need a hitch like:


https://www.etrailer.com/Trailer-Hit...eID=2002302798

and then you need a ball mount, ball, and pin like this:

https://www.etrailer.com/Trailer-Hit...rt/C45534.html

I think that uhaul mostly requires a 2" ball. There are cheaper hitches with a lower weight rating that use smaller components.

I dont know what the blue connector is.


George
 
Old Aug 22, 2020 | 11:53 PM
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Originally Posted by GeorgeLG
You don't list the year of your truck so I cant be certain of your wiring but in a 2002, there is a 4 wire fused provisional wiring harness for trailer lights provided by the factory that runs to the back of the truck underneath and is tucked up near the spare tire. This harness wires need to be connected to a receptacle like:

https://www.etrailer.com/Wiring/Tow-Ready/30717.html

And then you need this adapter to translate from your new 7 pin socket to the std 4 pin uhaul harness:

https://www.etrailer.com/Wiring/Hopkins/47345.html

Then you need a hitch like:


https://www.etrailer.com/Trailer-Hit...eID=2002302798

and then you need a ball mount, ball, and pin like this:

https://www.etrailer.com/Trailer-Hit...rt/C45534.html

I think that uhaul mostly requires a 2" ball. There are cheaper hitches with a lower weight rating that use smaller components.

I dont know what the blue connector is.


George

Sorry, it is a 2002.
Mine is also 2-door with the 19 gal fuel tank in the back, so my spare tire isn't underneath. The spare tire carrier is inside the hatch area.

Could that deadend wire be the 4-wire fused provisional?
 
Old Aug 23, 2020 | 12:00 AM
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I'm trying to Google what that blue plug is. I'm uncovering some discussion that suggests it's for the electric brake on trailers, but I haven't been able to confirm it yet.
 
Old Aug 23, 2020 | 12:42 AM
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Originally Posted by RedValor
Sorry, it is a 2002.
Mine is also 2-door with the 19 gal fuel tank in the back, so my spare tire isn't underneath. The spare tire carrier is inside the hatch area.

Could that deadend wire be the 4-wire fused provisional?
It should be. Look for brown/yellow/dk green/lt blue wires.

George
 
Old Aug 23, 2020 | 09:57 AM
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BTW. if you are keeping the cost down then as I said, you can buy a lighter hitch and also you can skip the plug and adaptor and just attach this to your wiring:

https://www.etrailer.com/Wiring/Chev...ID=20021170584

I started off with this wiring solution but it's not very sturdy and when the rental place broke off the ground pin and ruined my work day I went to the solution that I posted below. Also, there may be some risk on the lower hitch rating because uhaul has been getting more strict on verifying your total towing capacity.

George
 
Old Aug 23, 2020 | 06:58 PM
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I would be cheaper and easier to just rent a truck from Home Depot or the like than renting a trailer from UHaul for the day. Better yet, ask a buddy if you can borrow their truck for the day. You can put a ball in the bumper by cutting out the square piece of plastic above the hole (center of the bumper). If you do plan on towing more in the future, you'd be better off just getting a receiver and wiring up the flat 4 pin plug.
 
Old Sep 3, 2020 | 06:04 PM
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that "blue plug" is a splice pack, dont mess with it too much.
 
Old Sep 3, 2020 | 08:27 PM
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That bundle with the dead end wires is your trailer wiring. You'll need to buy the connector harness with a trailer plug on it and connect it. You only need four wires but there are six (I think) in that bundle. I'm thinking you need white for ground, brown for trailer lights, yellow and green for turn signals. I may be off on the green but the harness comes with your color codes. The plastic piece on the bumper just pops straight up. Go straight up, not on an angle or you'll break some of the tabs. Then you can easily cut out the square to expose the hole for the ball in the bumper. I soldered my trailer harness on and heat shrinked the wires.
 
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