Fixing an Electrical Wiring Problem

How to Fix an Electrical Wiring Problem: How can I install outlets on a wall of a new garage? I was going to put a GFCI outlet in the first outlet, but I am confused by the wiring. © By: Dave Rongey

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Wiring a GFCI Outlet

Electrical Question: How can I install outlets on a wall of a new garage? I was going to put a GFCI outlet in the first outlet, but I am confused by the wiring.

Wiring a GFCI Outlet

Mark asks:

• I need to install 3 outlets on a wall of a new garage. I was going to put a gfci in the first outlet, but I am confused by the wiring. the north garage wall yellow jacket starts with a black wire in a 20a fuse and a red wire in a 20a fuse in the breaker box.
• In the 1st outlet, there are 3 yellow jackets. a short black and red wire twisted and capped, 2 short white wires capped with a pigtail out to join up with a long white wire from that into a cap joined by another white wire.
• Two long black wires splashed with white paint and capped. 3 ground wires capped with a pigtail.
• I was going to put a gfci in. My note from the electrician who wired was the twisted black is line with white, then if another black is load. red ties through for another circuit for gfi. I have pictures as well.

Dave’s Reply:

Thanks for your electrical wiring question Mark.

How to Wire a GFCI Outlet in a Garage

Application: How to Wire a GFCI Outlet inside a Garage.
Skill Level: Intermediate to Advanced – Best performed by a Licensed Electrical Contractor, or Certified Electrician.
Electrical Tools Required: Basic Electricians Pouch Hand Tools, Voltage Tester, and appropriate Safety Gear.
Estimated Time: Depends on the personal level experience, ability to work with tools, install electrical circuit wiring, and the available access to the project area.
Electrical Safety: Identify the electrical power source to the GFCI Outlet, turn it OFF and Tag with a Note before working with the electrical wiring.
Electrical Wiring Parts and Materials: Electrical parts and materials for the GFCI Outlet should be approved for the specific project and compliant with local and national electrical codes.
Electrical Codes and Inspections: Installing or changing home electrical wiring should be done according to local and national electrical codes as adopted in your specific area of Montana. A permit and inspections may also be required.

How to Wire a GFCI Outlet in a Detached Garage

This electrical wiring project is about How to Wire a GFCI Outlet in a detached Garage.

Wiring GFCI Outlets in a Garage
First Reply from Dave:

• Mark, from the information you have provided, the electrician has pre-wired for two GFCI circuits, and from the number of wires that have been installed there are other devices that are part of the circuit wiring as well.
• Pictures are helpful, however tracing and testing the wiring will be required to reveal the actual circuit wiring configuration.
• Once this is understood then the wiring connections can be applied for the main GFCI outlet, and then the following outlets that will be connected.

Discovering the Installed Wiring
Reply back from Mark:

• So far what I have discovered is this, the red wire circuit is attached to a different black wire in the box.  When that circuit is on, the downstream outlets have power.  With the black wire circuit off, the light switch and lights are off.
• I separated the two long black/white paint wires, which were twisted tightly together, and the two long white wires – also twisted tightly together, and got 122 and 125 volts from the two white wires and one of the undone black/white paint wires.
• I guess I don’t understand this, I figured the long sets of wires would be for a GFCI, but the red wire is attached to the power wire to the outlets it seems, and it and the black wire it is attached to are short and in the back of the single gang box.
• The light switch and 3 lights were added in later, and the 2^nd outlet of the 4 on that wall was turned into a switch, with a yellow jacket going up to a new outlet on the ceiling, attached to a yellow jacket from a hole punched in the wall.

The Original Installed Wiring
Reply from Dave:

• I think you may need to recall the original installation, and how it was laid out with the installing electrician. There had to have been a plan of what was needed and where the locations would be.
• It may help you to know that when a black or red wire is marked white, this indicates that the wire is being used as a neutral wire.
  Also, a GFCI outlet is wired as the first outlet, and the Line and Load wiring configuration must be attached right for the GFCI to work.
• If the original wiring configuration has been altered without keeping track of what goes where and why, then things will not work right. At that point it is necessary to learn the basic fundamentals, or consider calling the electrician back to give you a hand.
• There are a lot resources that cover all of this on the website to help you.
• No – this is not always easy. I have been called out to jobs where a homeowner has not wired something correctly, or the previous electrician walked off the job site for some reason. It does take time and some testing but it always gets worked out.

Previously Installed Wiring
Reply back from Mark:

• Yes, that was the problem, the construction stalled out, and the first electrician moved to another state. Years have passed, I paid the contractor quite a bit of money for the next stage, and he didn’t finish it for a year and a half after being paid, and we still don’t have many doors or trim.
• The building is 2 halves, one side is a garage, the other side is a rec room/bathroom/bedroom. I was doing floors, installing outlets, lights, chandeliers, projectors, 3 way switches, fans etc., and ran into trouble in the garage when I discovered that there was a red wire by one door, but none at the other door.
• I couldn’t figure it out, so had a master electrician come out, and it took him several days of just trying to figure things out, in order to get lights to work etc., and It turned out the wiring was swapped incorrectly between the two halves of the building, and we had to drill through the wall and get the other red wire etc. back in the garage where it belonged for the switches to work properly there.
• Finally after getting everything painted and subsequent installation of the remaining outlets in the garage, I ran into this confusion. All that I thought would be on that side of the garage were some outlets in the wall.
• The second electrician installed a switch for 3 lights underneath a loft in that area, but he had nothing to do with the original wiring in the walls.
• There is a light in the storage loft above this area, perhaps that is something to do with this – the only way it turns on at the moment is with the light switch by the garage entrance that turns on the other ceiling lights.
• It’s kind of a case where the original electrician had definite ideas about how things should be, and I wasn’t too fussy about it and consequently I don’t understand some of the things I’ve encountered. Thanks, Mark.

How to Identify the Electrical Wiring
Reply from Dave:

• So with all of this in mind, basically all of the circuit wiring needs to be identified that enters the garage, starting with what is now working.
• With the power off:
  Go to all of the switch boxes and fixture boxes that do not have power and create a test loop of each wire set, where you take the black and white and twist them together to create a loop. Then go to all the boxes in the area and use a continuity tester to look for the loop wire set.
• Or – basically the same way – use a continuity tester with a audible tone, and use a wire nut to connect each test lead to a set of wires, then go through all the sets of wires in the area and connect the black and white wire together and listen for the tester tone.
• Either way you choose to do this, you are able to trace down the wiring.
• Create a diagram of what wire goes where.
  Identify the wire sets using masking tape and a marker pen.
• Once this is all done the wiring just needs to be made up correctly for the intended functions.
• This can be tricky so you will probably need help, especially with feeding power to other boxes correctly and making up the switch wiring.
• Hang in there, I have done this several times. The problem is the walls are all closed up so that makes it a lot harder – but it is possible.

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