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Common AC Wiring Issues & How to Fix Them

Cassie Pound, owner of Quality Heating, Cooling, Plumbing & Electric
Published by
Cassie Pound
November 20, 2022
Common AC Wiring Issues & How to Fix Them

We provide expert HVAC services that restore your home’s indoor comfort quickly and efficiently. Call 918-212-0122 today!

A malfunctioning HVAC system makes your home uncomfortable and uses an unfortunate amount of power. Diagnosing the problem could include checking the wiring. AC wiring issues can make air conditioner repair more difficult, especially if you don’t have experience working with electrical parts.

Some signs of electrical problems are more evident than others. Knowing what to look for can guide you in repairing electrical issues. You may think you can undertake AC repair as a DIY project, but professional AC repair in Tulsa delivers expert electrical work, resulting in long-lasting repairs and a lower chance of fire or electrical damage.

Below are common AC wiring issues and possible resolutions.

Foul Odors

Electrical wiring problems can produce strong smells, like melting plastic, burning rubber, or a fishy odor. These odors indicate a potentially dangerous electrical problem with your HVAC unit. If you smell burning when your AC kicks on, turn it off and call a professional immediately.

Short Cycling

Loose or faulty wiring may cause your HVAC system to short cycle or turn on and off for increasingly short periods. Before checking your wiring, you can inspect other system components, like your filter, refrigerant, and evaporator coils, as these parts can also cause short cycling.

Increased Electric Bill

Wiring issues can cause your electricity bill to skyrocket. Problems like short cycling cause more energy consumption, so check your HVAC wiring if you notice a jump in your bill.

Thermostat Not Working

If your AC doesn’t respond to thermostat controls like temperature changes, turning on or off, or using only the fan, you may have electrical problems. A professional can help determine whether the HVAC unit or thermostat needs repairs or replacement.

Tripping the Circuit Breaker

Circuit breakers have built-in safety mechanisms to protect you and your home from faulty wiring. If your HVAC system has a problem with the wiring, it could flip your circuit breakers. Repeatedly tripped breakers require an inspection from licensed electricians who know how to safely work on electrical panels and HVAC systems.

How to Fix AC Wiring Issues

If you’re determined to fix your AC wiring issues yourself, check out the most common problems and how you can repair them.

Exposed Wires

The wires inside your HVAC system have an insulated casing made of rubber or plastic. This casing prevents the wires from damage like fraying, corrosion, or separation. If you open up your HVAC system and see split or damaged wire casings, you may need to replace the wires.

In a pinch, you can use electrical tape to wrap the wires and keep them from experiencing further damage. Electrical tape doesn’t constitute a permanent solution, so plan to replace the wires or have an electrician do it for you down the road.

Loose Wires

HVAC units vibrate while running, which can cause wires to loosen from their connections. Loose wires can’t properly channel electricity throughout your unit, making it stop working or work intermittently. You can sometimes tighten these wires yourself, but remember to turn the electricity off before working on them.

Faulty Wiring

DIYers often believe they can wire up their HVAC system using online guides or YouTube videos. While some people have this ability, not all homeowners can safely and correctly connect their HVAC system’s wiring. Faulty wiring causes problems with your unit’s functionality and, in several cases, causes dangerous electrical fires.

If you suspect faulty wiring in your HVAC system, contact a professional electrician to inspect, troubleshoot, and repair the problems.

Repairing AC Wiring

Before repairing AC wiring issues, you’ll need the right tools, such as:

  • Adjustable wrench
  • Cordless drill or driver
  • Insulated screwdrivers
  • Needle-nose pliers
  • Socket and ratchet set
  • Nut driver
  • Multimeter
  • Voltage tester
  • Flashlight

You should also check your HVAC system’s manual for information on your unit’s wiring. Some manuals have wiring guides, while older units may have their manuals online. If you have never worked on electrical wiring before and can’t find information on your unit’s layout, hire a professional HVAC tech, so you don’t cause more damage.

Step One: Turn Off the Electricity

Turn your HVAC unit off, then turn off the breakers at the main electrical panel. This prevents you from accidentally electrocuting yourself or starting an electrical fire.

Step Two: Test Electrical Parts

Check out your unit’s fuses with your multimeter to see if they’ve blown. Blown fuses may indicate a problem with your condensing unit, requiring you to purchase a new part. You’ll want to replace the condensing unit and the fuses before turning your HVAC system on again.

Step Three: Inspect the Access Panel

Open your unit’s access panel and take a look at the wiring. Get up close and use your flashlight to check every wire, turning them and tugging them to eliminate broken wires, split casings, or loose connections. You should also look for signs of pests, like nests or chewed wiring.

Step Four: Replace Problematic Wiring

If you notice any problems with your wiring, replace them. Ensure that you tighten your wires correctly and follow your wiring map to ensure proper placement.

Step Five: Test the Repairs

Close up your access panel and turn on your circuit breaker. Return to your HVAC unit and turn it on as well. Finally, turn your thermostat to its lowest setting and see what happens.

If your HVAC system starts up without any problems, congratulations, you’ve repaired the wiring problems. Should your AC still not work correctly, you may need to replace other parts or consult a professional electrician or HVAC technician.

Trust the Professionals at Quality Heating, Cooling & Plumbing in Tulsa, OK

Troubleshooting and repairing AC wiring issues can frustrate many DIY homeowners, especially if the problems affect the functionality of your whole HVAC unit. Our Quality Heating, Cooling & Plumbing team provides professional HVAC service by licensed electricians and HVAC specialists. When you need the best AC repair in Tulsa, OK, or want to know about tax rebates for new AC units, call us at 918-221-0122.  

Cassie Pound, owner of Quality Heating, Cooling, Plumbing & Electric
Published by
Cassie Pound

Cassie Pound is the Vice President of Quality Heating, Cooling, Plumbing & Electric with locations in Tulsa, Glenpool, and Bartlesville, Oklahoma.