7 Pin Connector

wlvrn1215 · August 25, 2008

got a question...on my truck what exactly are the wires for that are next to the fuse box under the hood I hooked up my buddies trailer the other day and my 7 pin didnt work. The Lights wouldnt work. He hooked it up to his 89 Dodge and it worked just fine...what gives there is also another plug tucked by my spare I found the other day. Now what the hell is that. If someone could PM me or something with the answers that would be awsome

dietz4ibanez · August 25, 2008

If you do a search you will find a thread for all you need... But I think that you need to get a "t" splice to continue your original lights and the trailer lights will come out of that T... The wires in the fuse box are there for you to hook up trailer brake...

wlvrn1215 · August 25, 2008

I have the trailer package and a stock 7 pin connector. What is the extra plug by the spare tire???

minibike132 · August 25, 2008

What does the extra plug look like?

wlvrn1215 · August 25, 2008

just a connector ....like something gets plugged into it just found it the other day

minibike132 · August 25, 2008

Quick question, there is supposed to be a owner's manual supplement that should have been included with your owners manual. It should be tittled SEO 9L4 Wiring Provisions 12 Volt Power Supply - Chevrolet Silverado and GMC Sierra. Did you get that? I don't know if it answers any of your questions but you should have it and it might.

Edit: I'm just going to post the whole thing incase anyone did not get the supplement. What follows is from the 2007 supplement for RPO 9L4 if that doesn't describe your truck this might not apply.

Your vehicle is equipped with wiring provisions for a 12-volt power supply (SEO 9L4). Refer to the following information when adding electrical accessories that will use the 9L4 12-volt power supply feeds connected to your vehicle's electrical system. After reading the following information, keep it with your owner's manual for future reference.

Electrical Connections

Notice: Before modifying or adding any wiring, be sure that it will work properly with your vehicle's wiring system. Because there are so many modifications that can be made for many different bodies and accessories, GM cannot take responsibility for any changes made. Such changes may not be covered by your GM Warranty. Have the work done by an experienced electrical technician.

All wiring must be properly protected by fuses, etc. and must be routed properly so that it will not be cut, pinched or rubbed by other parts of the vehicle. Do not route wiring in areas where it will be very hot. Be sure not to overload the vehicle's wiring, connectors and components. All added wire must be at least the same size as the wire being attached to for proper fuse protection.

Installation Instructions -- 12 Volt Accessory Power Supply

Disconnect the negative (-) battery cable at the battery. The negative (-) battery cable must be disconnected before the positive wiring lead is connected to the power accessory.

Locate the power supply harness under the instrument panel near the center of the vehicle. The wire bundle consists of six blunt cut wires, two red/white (battery hot), two black (ground), one light green (Ign hot) and one light blue (Ign hot).

Remove the tape to release the wire bundles from the power supply harness.

The IGN A and IGN B wires have voltage supplied and are hot when the ignition is turned to ACC, RUN or RAP (Retained Accessory Power).

The BAT A and BAT B wires have direct voltage supplied and are hot at all times.

The combined electrical load of IGN A and BAT A must not exceed 21 amps (250 watts). Additionally, the combined electrical load of IGN B and BAT B must not exceed 21 amps (250 watts). The combined electrical load of all circuits must not exceed 42 amps (500 watts).

Prepare the wires that are to be used to connect the power accessory. Do not remove the unused wires. Tape unused wires back in their original position under the instrument panel.

Complete the wiring installation of the customer added accessory with additional wire required for the specific electrical accessory power connection. The wire gage, 12 gage (3.0 mm²), should be the same as the wiring of the installed harness.

The ignition must be turned to OFF or ACC prior to attaching the cables to the battery, or serious damage to the Vehicle Control Module (VCM) may result.

The windshield wiper switch and the radio must be turned off before attaching cables to the battery.

Reconnect the negative (-) battery cable to the battery. Torque the bolt to 3.7 lb-ft. (5 N·m).

Reset the clock time and radio pushbuttons as desired.

Servicing Relays and Fuses <A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1818642&pubCellSyskey=74449&pubObjSyskey=1818642&from=sm&laborOpCode=&cellId=74449#oth1-1818642">

Exploded View of Instrument Panel

<LI type=A>Relays and Fuses

<LI type=A>Front of the Vehicle

<LI type=A>Floor of the Vehicle

<LI type=A>Glove Box
Tab

The following information tells you how to access your vehicle's relay and fuse center for checking and replacing fuses/relays.

The fuse and relay center is located behind the right side of the glove box. Remove contents from the glove box. Push the tab on the inside of the box upward and pull the box out of the opening. Set the tray down gently toward the floor. It will hang from the hinge.

The fuse and relay center can be accessed by unscrewing the two 4 mm screws that hold the bracket to the instrument panel structure. Replace a 30 amp mini fuse with a GM Part No. 12092075 fuse, or equivalent. Use a fuse puller if your vehicle has one. Replace a relay with a GM Part No. 12193604 relay, or equivalent.

After servicing the center, reinstall the relay center to the instrument panel structure using the two screws torqued to 1.9 lb-ft. (2.5 N·m).

Reinstall the glove box into the compartment by lifting it into the instrument panel while pushing the tab upward.

minibike132 · August 25, 2008

I have the trailer package and a stock 7 pin connector. What is the extra plug by the spare tire???

How many pins? Male or female, a picture would sure help if you could get one.

Outbacker · August 25, 2008

I always thought the extra plug in was for a camper that you carry in the box. This plug in is for charging the camper battery and for powering the camper 12 volt stuff.

wlvrn1215 · August 25, 2008

Sorry I had to go Mike...my wife has been sick and Had to check on her..... the plug is a female.

c4cruiser · August 25, 2008

got a question...on my truck what exactly are the wires for that are next to the fuse box under the hood I hooked up my buddies trailer the other day and my 7 pin didnt work. The Lights wouldnt work. He hooked it up to his 89 Dodge and it worked just fine...what gives there is also another plug tucked by my spare I found the other day. Now what the hell is that. If someone could PM me or something with the answers that would be awsome

The wire for the 12v pin in the trailer lights connector is taped to a harness under the brake master cylinder. It attaches to Stud #1 on the fuse panel. When you install the J-case 40A fuse in position #68, that will powere up the lead. The wire betweenthe fuse box and fender is some other 12v accessory wire.

As far as the extra connector back near the trailer light connector, it's for an additional 3rd brake light. If you have a canopy shell that has a 3rd brake light, connect the wire from that to the extra connector. You can also use it for those lighted hitch inserts.

compulynx · August 25, 2008

Back to his original question, the lights SHOULD have worked. The wires under the hood are for the trailer power and the trailer brake. However, from what I understand, the turn signal and brake lights should work without those 2 wires connected.....

I am assuming when he said "the lights did not work", he meant the turn sigs, running and brake lights...

If I am wrong, someone will correct me....

C