Correct Trailer Hitch and 7-Way Wiring Setup for a 2005 GMC Sierra 1500 Short Bed 2WD Pickup  

Question:

Expert Reply:

Hi JD, great question and thank you for all of the helpful info!

Based on the information you provided, it sounds like you have a standard 2005 GMC Sierra 1500 short bed pickup and not a 1500HD, but I do want to verify whether it is a regular pickup bed or a cab and chassis style work truck before locking in the hitch recommendation since that changes fitment quite a bit. I am not able to look up the VIN.

If your truck has a standard pickup bed, the etrailer Trailer Hitch Receiver part # e98849 is a really solid fit as long as the truck does not have a Tommy Gate lift or a 10 inch drop bumper. If your truck has a roll pan bumper instead of a standard step bumper, then the Curt hitch part # e82AR would be the better choice because it is specifically designed around roll pan clearance.

Both hitches include the complete installation hardware kit with the necessary bolts, nuts, washers, and mounting hardware needed for installation, so you would not need to source those parts separately.

For the trailer wiring, these hitches do not have a built in 7-way connector mount, so you would add a separate mounting bracket like part # 306-X6020 to attach the 7-blade connector near the receiver. Since your truck does not currently have the factory trailer wiring receptacle, you would also need to add a 7-way wiring setup separately depending on whether you need trailer brakes and auxiliary power functions.

Before I point you toward the exact hitch and wiring parts, can you confirm whether your truck has a standard pickup bed or if it is a cab and chassis style work truck setup?

What do you plan to tow first, work equipment, a small camper, or a boat?

expert reply by: Heather A

0

Jd

5/21/2026

Truck is standard bed 6 foot. It is not a cab and chassis, it is a regular extended cab pickup with regular pickup bed. It is not a work truck missing the bed nor upfitted whatsoever. Truck does not have a Tommy Gate lift or a 10 inch drop bumper. Truck has normal stock from factory rear step bumper. Beings the truck does not have any receptacle for trailer lights, is there a plug in play wiring harness for just tail lights, brake, and turn signals beings we do not need trailer brakes nor auxiliary power functions? For the factory capped ends that are glued that must be stripped and wired into the new trailer light receptacle, what part number is compatible for a 2005 GMC sierra 1500 that never was configured for trailer light 7 blade socket receptacle? Will hitch etrailer Trailer Hitch Receiver part # e98849 easily bolt on self contained with all its hardware without modification to the 2005 GMC sierra 1500 stock factory frame-sub-frame beings the bumper is stock and left alone from the factory? Will there be enough clearance without being too low to ground thus not too low to the ground as it bolts to the bottom of the step bumper?

Heather A.

5/21/2026

@Jd Perfect, thank you for clarifying all of that. In that case, the etrailer Trailer Hitch Receiver part # e98849 is absolutely the correct fit for your 2005 GMC Sierra 1500 extended cab short bed with the standard factory step bumper and factory frame. It is a fully bolt on installation and does include all of the required mounting hardware including the bolts, nuts, washers, and spacers needed for installation. There is no drilling or modification required to the frame on your setup. Ground clearance is actually pretty good on these trucks with that hitch as well. Even though the receiver sits below the bumper, it tucks up fairly close to the factory step bumper. Since you only need basic trailer lighting for tail lights, brake lights, and turn signals and do not need trailer brakes or auxiliary power, you can keep things much simpler and use a standard 4-way flat wiring harness instead of a full 7-blade setup. The Curt T-Connector part # C55384 is the correct plug and play harness for your truck as long as the factory capped GM trailer wiring connector is present at the rear of the truck. Most 2005 Sierra 1500 trucks do have this connector from the factory even if they never came with trailer wiring installed, though there were some very base or fleet configurations where wiring varied slightly. You would typically look underneath near the rear bumper on the driver side frame rail area, usually above or just forward of the spare tire. On many trucks the connector is clipped to the frame near the rear crossmember and covered with a gray or black weather cap from the factory. The Curt harness simply plugs directly into that connector without cutting or splicing into the truck’s factory wiring, which makes it a very clean setup. If you do not find that factory connector on your truck, let me know and I can point you toward a hardwired 4-pole wiring setup instead. That style taps directly into the tail light wiring behind the truck and still gives you the basic trailer lighting functions you need. Let me know what you find!

Jd

5/21/2026

@HeatherA. A four pin will not be compatible with the trailer lighting we have. Beings we need a 7 blade round receptacle for plug that is on the trailer, even though there is no trailer axle brakes nor accessory charge, if the truck was ordered bare without any wiring nor receiver, do you have a harness tap in on the driver side frame rail area, usually above or just forward of the spare tire covered with a gray or black weather cap from the factory for that connector that will be covered in glue or will the wires need to be spliced and ends stripped to fasten the leads into the new harness? Or is this a direct plug in clip together wiring harness with both sealed ends that plug in together without tap nor splice? What is this part number for harness connector for a 7 blade receptacle? Even if we are only connecting the brake, stop, turn signal, four way, and running lamp park light trail light leads?

Jd

5/21/2026

@HeatherA. If the truck has a very base configuration and is absent from the trailer wiring harness, will it still have factory harness tap in on the driver side frame rail area, above or just forward of the spare tire covered with a gray or black weather cap from the factory for that connector that will be covered in glue or will the wires need to be spliced and ends stripped to fasten the leads into the new harness? Will this be compatible with connecting the leads for a 4 pole into a 7 blade socket? Is there configurations that do not have a socket harness connector for any gray or black weather cap from the factory for that connector that will be covered in glue under the factory weather seal cap? Regardless do all 2005 GMC Sierra 1500 base model pickups have the connector to plug and play or will splicing leads or tapping be required to connect the leads for stop turn tail function as would for 4 pole except into the 7 blade round receptacle for 7 blade socket compatible trailer plug?

Heather A.

5/21/2026

@Jd Got it, thank you for clarifying. In that case, yes, you can still use a 7-blade round connector even if your trailer only currently uses the lighting functions and does not have trailer brakes or auxiliary power connected. If your truck has the factory capped GM connector near the rear frame rail area by the spare tire, the Curt part # C55774 is the plug and play 7-way harness setup you would want. That harness uses sealed factory style connectors and plugs directly into the truck’s existing GM wiring connector without cutting, splicing, stripping wires, or dealing with glued wire ends. It is designed specifically for trucks that have the factory tow wiring provisions already present at the rear of the frame. Most 2005 GMC Sierra 1500 trucks did come with that capped factory connector even if they were not originally ordered with a hitch or trailer wiring, You would need to get underneath the truck and check near the driver side frame rail area around the spare tire and rear crossmember for a gray or black capped connector clipped to the frame. The extra pins for trailer brakes and auxiliary power on the 7-way would simply remain unused unless you decide to add those functions later. The nice part is it still gives you the proper 7-blade socket style your trailer already uses while keeping the installation clean and factory style. If you do not find the factory capped GM connector under the truck, you can still absolutely add the 7-blade connector your trailer uses. In that case, you would use the Curt Powered Tail Light Converter part # C59236 along with the Curt 7-Way RV-Style Connector part # C57672. The converter handles the truck’s tail light, brake light, and turn signal wiring, while the # C57672 gives you the standard 7-blade socket style at the rear of the truck. Since you are not using trailer brakes or auxiliary power right now, those pins on the 7-way would simply remain inactive unless you decide to add those functions later.

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