trailer wiring

iron_786 · February 12, 2004

just curious, is there a pigtail or a plug in somewhere under the vehicle or do i have to go under and splice wires to install wiring for a trailer plug, i usually only use the flat 4 wire hookups but i kinda would like one of those plug boxes as the the open wire ones seemed to get damaged on me all the time, carwash etc....

tmoreau · February 12, 2004

...somewhere under the vehicle...

On some vehicles yes, on some no. What are you driving? On 99+ silverados there is a harness by the spare tire.

97whitez71 · February 12, 2004

Go to www.draw-tite.com then click on electrical, then click on T-One Connectors. That is what I have on my truck. You can get these at Autozone, NAPA, etc. Hope this helps.

iron_786 · February 12, 2004

sorry about that its a 2002 siverado ls,,,,,ext cab 4*4

redvett · February 12, 2004

If your truck has the Z82 HD option it has a platform hitch and trailer connector to the left of the hitch. You may want to look at the harness behind the step bumper there should be a flat connector there taped to the lighting harness. What ever you do (never cut the harness to make the hookup.) Use a connector kit that plugs in other wise you will be having electrical problems later on.

varmint2506 · February 12, 2004

Generally if the truck has a towing package it will have a trailer wire set. They tend to hide quite well with a lot of tape.

03GMCSierra4.8L · February 13, 2004

Iron_786

You will find a connector zip tied to the cross member behind the bumper and near the spare. This connector will have a dummy cap on it that you will need to remove. All you will have to do is go and buy an adapter that will plug into this connector. You can get either a round 7 pin or the flat 4 witch ever you like. Walmart has them under the Hoppy brand name for around $10-$25 depending on wether its a 4 or 7 pin.

Other then that you a ready to go. The truck is prewired for all the lights and even the 12V pos feed and Brake feed for the trailer. If you need Elect Brakes you will also need to buy a Brake controller and harness for under the dash.

Hope this helps.

iron_786 · February 13, 2004

thanks for the info people tom i will have a look under the thing and maybe get this project underway!

tmoreau · February 13, 2004

Just a note, on my 2001 silverado (no options, hd, trailering, etc) there was about an 18" pigtail zip tied up there between the spare and the bumper. The ends of the wires were dipped in wax and taped up in a bundle, I bought one of the seven pin plugs for my truck from farm and fleet and installed it in the parking lot. I had to strip the ends of the wires but otherwise there was no modifying the trucks wiring at all.

JayMan · February 13, 2004

If you read your owner's manual, all the +1999 NBS trucks have a basic flat 4pin harness taped/wrapped near the back bumper/spare tire somewhere on the frame or crossmember. Depending on assembly plant, it can be quite an Easter Egg Hunt trying to find exactly where.

If the truck has a factory receiver hitch, it has the HD round 7 pin connector next to the left receiver tube safety chain guide . You can go to any auto parts store, or U-Haul place, and get an adaptor that converts 7pin round to 4pin flat: it plugs right in. Mine cost $7.

These trucks are easy to equip for towing even if they don't have factory HD tow options: the days of butchering wires and having them fall apart 5 years later is over with.

You know, the "good 'ole days."

iron_786 · February 13, 2004

well i had a good look and i found a crop of dead end wires, no pig tail that i can find, there is a junction block on the drivers side at the back where harness split and goes to each light, im thinking this plug in must have been an option, and i just didnt get it. this crop of dead wires seems to insulated quite well like a factory job. i took a pic but i cant figure out how to post it on here

JayMan · February 13, 2004

well i had a good look and i found a crop of dead end wires, no pig tail that i can find, there is a junction block on the drivers side at the back where harness split and goes to each light, im thinking this plug in must have been an option, and i just didnt get it. this crop of dead wires seems to insulated quite well like a factory job. i took a pic but i cant figure out how to post it on here

That doesn't sound right.

There should be a factory-terminated end, like a WeatherPak connector. If the wires are just cut off, corrosion can start to work its way in.

I hope some a**hole didn't chop the connector off.

The owners manual for my 2000 clearly shows three possibilities: with NO towing package, a basic 4wire flat connector secured to the rear frame somewhere near the rear bumper/spare tire; with Z82 towing package the HD round 7way connector next to the receiver; with Z82 AND the optional 5th wheel harness, an additional long wire harness secured to the frame near the front of the box (No connector but is factory-sealed to protect the wire harness).

CdnChevy · February 14, 2004

Out of curioisty where do they hide the "5th wheel" wiring? I presume up by the front of the box somewhere?

JayMan · February 14, 2004

Out of curioisty where do they hide the "5th wheel" wiring? I presume up by the front of the box somewhere?

Somewhere along the frame near the gas tank fil hose.

Remember the 5th wheel wiring harness is optional and above just the Z82 towing package, and is not included with the Z82 towing package.

The truck will not be equipped with 5th wheel wire harness unless factory-built with that option.

03GMCSierra4.8L · February 14, 2004

Iron_786

If all you found was wires with no connector, then its my guess they got chopped off! My 03 and I believe your 02 should of had what I described to you. A round connector that is capped with a dummy cap that you can either plug a 7 pin pigtail into or a flat 4 pigtail which you can buy at Wal Mart or the like. Mine did not come with the 4 pin flat all pre wired. Just the ability to either add the 4 pin or the 7 pin round, like the type included with the tow package.

Its my guess at this point you will have to probe the wires that are loose and determine what is what and hard wire a connector on to it.

Terry.