Trailer Wiring Adapter

[KCKKen]

Hi Everyone!

As I'm upgrading the 78 C20 and working towards the wiring on the 85 GMC I was wondering if anyone has any experience with a plug-in trailer wiring adapter for a flat 4-pin trailer plug? This would be separate from the car trailer wiring, I have a pickup bed trailer that doesn't have brakes and an even smaller trailer I use for my riding mower that just have the flat-4 connection.

I found one on Amazon and am about to pull the trigger on buying it, but wanted to see if anyone knows of other options:

https://www.amazon.com/dp/B001GBG8KS/

I find it odd that it breaks the applicability at 1984, I don't remember seeing anything different on the 1985 when I took it apart.

Take Care,
KS in KCK

 

[squaredeal91]

I have the exact same adapter in the packaging. Haven't used it yet but thought it was a really cool idea.

 

[CalSgt]

I have the exact same adapter in the packaging. Haven't used it yet but thought it was a really cool idea.

I thought so too…. I had no idea these even existed. I would have just cut into the factory wiring, but this is way better

 

[squaredeal91]

I thought so too…. I had no idea these even existed. I would have just cut into the factory wiring, but this is way better

Exactly , I almost cut mine then just ran butt connectors and made it work. Then discovered they make a clean plug and play. I'm saving it for when I put the bed back on.

 

[Turbo4whl]

Hi Everyone!

As I'm upgrading the 78 C20 and working towards the wiring on the 85 GMC I was wondering if anyone has any experience with a plug-in trailer wiring adapter for a flat 4-pin trailer plug? This would be separate from the car trailer wiring, I have a pickup bed trailer that doesn't have brakes and an even smaller trailer I use for my riding mower that just have the flat-4 connection.

I found one on Amazon and am about to pull the trigger on buying it, but wanted to see if anyone knows of other options:

https://www.amazon.com/dp/B001GBG8KS/

I find it odd that it breaks the applicability at 1984, I don't remember seeing anything different on the 1985 when I took it apart.

Take Care,
KS in KCK

NAPA Sells one as well. May be cheaper. Local NAPA stocks them, you may need to ask you NAPA to check their catalog

 

[HotWheelsBurban]

NAPA Sells one as well. May be cheaper. Local NAPA stocks them, you may need to ask you NAPA to check their catalog

The trailer wiring harness adapters that plug in between the two halves of the rear wiring harness, should be the same for all square body trucks. If you have a Northern Tool store in your area, they have them too. Got mine from there, for my crew cab. The one on my Burb came from Rock Auto on closeout. They are another place to try, for these items; they usually have some version of it available.

 

[crpntr78]

The plug configuration is different after '84. 84 and under is round with I think spade connectors whereas the 85 and up are a smaller diameter with pin connectors.

 

[Snoots]

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[Oldbear42]

I run 7-pin RV-style connections on all my vehicles and I have adaptors to go to the four-pin for when I help move someone else's trailer (two friends' boat trailers are 4-pin and I often haul them to the lake as payment for staying at their cabins for the weekend). I ran a junction box at the back of my truck to make adding stuff like trailer plugs easier - I'm installing a chrome bumper soon and will install the 7-pin then.

 

[Broken85]

Hi Everyone!

As I'm upgrading the 78 C20 and working towards the wiring on the 85 GMC I was wondering if anyone has any experience with a plug-in trailer wiring adapter for a flat 4-pin trailer plug? This would be separate from the car trailer wiring, I have a pickup bed trailer that doesn't have brakes and an even smaller trailer I use for my riding mower that just have the flat-4 connection.

I found one on Amazon and am about to pull the trigger on buying it, but wanted to see if anyone knows of other options:

https://www.amazon.com/dp/B001GBG8KS/

I find it odd that it breaks the applicability at 1984, I don't remember seeing anything different on the 1985 when I took it apart.

Take Care,
KS in KCK

I started with the adapter bought but bought this guy, ran an extra hot, and a break wire, tapped the reverse lights and updated the whole truck to a 7/4/5 pin.

https://a.co/d/dgRajjx