Many homeowners run into this common problem: a new dryer comes with a 4-prong plug, but the outlet in an older home is a 3-prong receptacle. This mismatch exists because the National Electrical Code (NEC) was updated in 1996, requiring new homes to install 4-prong outlets for safety. Older homes, however, may still have 3-prong outlets.
This article will walk you through the process of converting a 4-prong dryer cord to a 3-prong cord, explain the wiring differences, and provide a wiring diagram. We’ll also cover the option of using a 4-prong to 3-prong adapter, and most importantly, highlight the safety risks involved.
⚠️ Safety Warning: Always disconnect the power before working. Dryers run on 240 volts, which can cause serious injury or death. If you’re not confident in your skills, hire a licensed electrician.
Understanding 3-Prong vs 4-Prong Dryer Plugs
3-Prong Plug (Old Standard)
Two hot wires (L1 and L2) providing 240V.
One neutral wire, which also acts as the ground.
Less safe, since neutral and ground share the same connection.
4-Prong Plug (Current Standard)
Two hot wires (L1 and L2).
One neutral wire.
One separate ground wire.
Safer, because the ground is independent.
What You Need Before Starting
Tools: Screwdriver, pliers, wire stripper, camera/phone (to record wiring before removal).
Materials: A new 3-prong dryer cord.
Power Safety: Unplug the dryer or switch off the breaker.
Step-by-Step: Converting 4-Prong to 3-Prong
Open the terminal block cover
On the back of the dryer, remove the access cover with a screwdriver.
Remove the old 4-prong cord
You’ll see four wires: red (L1), black (L2), white (neutral), green (ground).
Take a picture for reference.
Loosen the screws and remove the cord.
Prepare the new 3-prong cord
The cord has three wires: red (L1), black (L2), white (neutral/ground).
Connect the wires
Red → L1 terminal
Black → L2 terminal
White → Neutral terminal (center)
Important: Inside the dryer there is usually a grounding strap or wire. This must be connected from the neutral terminal to the dryer frame. This bonds neutral and ground together, as required in a 3-wire system.
Secure and close
Clamp the cord securely so it doesn’t pull loose.
Reinstall the cover plate.
Wiring Diagrams
4-Prong Dryer Cord Wiring
L1 = Red
L2 = Black
Neutral = White
Ground = Green
3-Prong Dryer Cord Wiring
L1 = Red
L2 = Black
Neutral/Ground = White (bonded to the dryer frame via strap)
Using a 4-Prong to 3-Prong Adapter
If you don’t want to change cords, you can buy a 4-prong to 3-prong adapter.
Pros: Quick, easy, no rewiring needed.
Cons: Less safe, since it eliminates the separate ground. Adapters can be a weak point over time.
Adapters should be seen as a temporary solution. For long-term safety, change the cord.
Conclusion
Switching a 4-prong dryer cord to a 3-prong is possible and safe if you follow the correct steps. The key step is bonding the neutral and ground at the dryer terminal.
👉 If you need the opposite conversion, check out our guide: “How to Convert a 3-Prong Dryer Cord to a 4-Prong: Upgrade for Better Safety”.
