At Fitz’z, it’s not about the cars –
It’s about the people who drive them!
Monday to Friday
From 8:00am – 4:30pm
At Fitz’z, it’s not about the cars –
It’s about the people who drive them!
Monday to Friday
From 8:00am – 4:30pm
There’s nothing more frustrating than turning your key and hearing nothing but a click—or watching your dashboard lights flicker like a haunted house while you’re driving down Lemay Ferry Road. Modern vehicles rely on incredibly complex electrical systems that control everything from your engine timing to your power windows, and when something goes wrong, pinpointing the exact problem requires more than guesswork. That’s where professional auto electrical diagnostic testing comes in. Here at Fitz’z Automotive Service in Lemay, MO, our ASE-certified technicians use state-of-the-art diagnostic equipment to trace every electrical issue back to its source—whether it’s a short circuit buried deep in your wiring harness, blown fuses that keep recurring, or a failing alternator that’s slowly draining the life out of your car battery. As a family-owned auto repair shop serving the greater St. Louis area for over 30 years, we’ve built our reputation on honest answers and thorough diagnostics. We don’t just read a code and start replacing parts—we dig deeper to find the real problem so you’re not paying for repairs you don’t need. Whether you’re coming from the Carondelet neighborhood, heading over from Oakville, or live right here off South Broadway, our electrical diagnostics service is designed to get your vehicle back to reliable performance fast.
Auto electrical diagnostic testing is a systematic process of evaluating every electrical component in your vehicle to identify faults, failures, and potential problems before they leave you stranded. Today’s vehicles contain miles of wiring and dozens of interconnected electronic modules that communicate constantly. A single faulty connection can trigger a cascade of symptoms—from a persistent check engine light to an ignition system that intermittently refuses to start. Professional electrical diagnostics use specialized tools and technical knowledge to decode what your vehicle is trying to tell you, saving you from the expensive trial-and-error approach of swapping parts until something works.
We recommend scheduling auto electrical repair diagnostics any time your vehicle exhibits unusual behavior that doesn’t have an obvious mechanical explanation. If your car struggles to start on cold Lemay mornings, if your headlights dim at idle, or if you notice strange warning indicators on your dashboard, these are all signals that your electrical system needs professional attention. Additionally, if you’ve recently had aftermarket accessories installed—such as a new stereo, lighting, or remote start—and started experiencing problems, a diagnostic test can reveal installation issues that may be affecting your vehicle’s factory wiring.
Every diagnostic session at Fitz’z Automotive Service begins with a thorough conversation with you about the symptoms you’ve noticed. Our technicians then perform a hands-on visual inspection, checking for obvious issues like corroded battery terminals, damaged wiring, blown fuses, loose connectors, and signs of rodent damage to the wiring harness. This initial assessment often reveals clues that direct the rest of the diagnostic process and can sometimes uncover simple fixes that save you significant time and money.
Next, we connect professional-grade OBD-II scan tools to your vehicle’s diagnostic port to retrieve stored and pending fault codes. While consumer-level code readers can give you a generic trouble code, our advanced scanners pull manufacturer-specific codes, freeze frame data, and live sensor readings that provide a much more detailed picture of what’s happening inside your vehicle’s electrical system. A code is a starting point—not a diagnosis—and our ASE-certified technicians understand the difference.
Once we’ve gathered initial data, we move into hands-on circuit testing. Using digital multimeters, we check voltage, resistance, and current flow through suspected circuits. Oscilloscopes allow us to visualize signal patterns from sensors, spark plugs, and electronic modules in real time, revealing intermittent faults that static measurements can miss. Load testers evaluate whether your car battery and charging system can perform under real-world demand. This level of testing is what separates professional electrical diagnostics from simple code reading.
For complex electrical issues, our technicians reference factory wiring diagrams and technical service bulletins specific to your vehicle’s make, model, and year. By tracing circuits from component to component, we can identify exactly where a short circuit, open circuit, or high-resistance connection exists. This methodical approach is especially critical when dealing with problems in the wiring harness, where multiple circuits run together and a single damaged wire can affect several seemingly unrelated systems.
Your vehicle’s charging system is the foundation of all electrical operation. We perform comprehensive battery testing to evaluate cold cranking amps, reserve capacity, and internal resistance. Alternator replacement is one of the most common repairs we perform, but we never recommend it without first verifying that the alternator has actually failed—not just that a worn belt, corroded cable, or faulty voltage regulator is mimicking alternator failure. Our thorough approach to charging system diagnostics ensures you only pay for what’s actually broken.
When your vehicle won’t start, the problem could originate in several places. We test the starter motor’s draw, verify the condition of the ignition system components including spark plugs and ignition coils, and check the starter solenoid and related circuits. Starter repair or replacement is performed only after we’ve confirmed the starter is the actual culprit—not a weak battery, corroded ground strap, or failing ignition switch. We also evaluate the neutral safety switch and anti-theft system, which are common causes of no-start conditions that get overlooked.
From headlights and taillights to interior lighting and power windows, your vehicle’s accessory circuits see heavy daily use. We inspect fuse panels for blown fuses and signs of overheating, test relay replacement candidates for proper switching function, and trace accessory circuits to find parasitic draws that can kill your car battery overnight. If you’re experiencing electrical issues with specific accessories, our circuit-level testing identifies exactly where the fault lies.
Modern vehicles use body control modules (BCMs), engine control units (ECUs), and controller area network (CAN bus) communication systems to coordinate virtually every function. When these advanced automotive electronics malfunction, the symptoms can be baffling—from random warning lights to features that work sometimes but not others. Our diagnostic equipment can communicate directly with these modules, read internal fault codes, check network communication integrity, and determine whether a module needs reprogramming or replacement.
Accurate Diagnosis Saves Time and Prevents Costly Repeat Repairs
The single biggest advantage of professional electrical diagnostics is accuracy. We’ve seen countless vehicles come to our Lemay shop after other facilities replaced batteries, alternators, and starters without fixing the actual problem. Proper diagnostic testing identifies the root cause the first time, which means you’re not wasting money on unnecessary parts and labor. Keeping your vehicle’s electrical system in top condition also helps maintain your vehicle’s overall reliability, and well-maintained vehicles can help you lower auto insurance costs by avoiding claims related to breakdowns and electrical failures.
Transparent Digital Vehicle Inspections Keep You Informed Every Step
At Fitz’z Automotive Service, we believe you deserve to see exactly what we see. That’s why we provide transparent digital vehicle inspections with photos, videos, and detailed notes sent directly to your phone or email. When we find a corroded connector, a damaged section of wiring harness, or worn electrical components, you’ll see the evidence for yourself before we recommend any repairs. This transparency is central to how we’ve earned trust in the Lemay community for over three decades.
Expert Testing Across All Makes Including Domestic, Asian, and European Vehicles
Whether you drive a Ford F-150, a Honda Accord, a Toyota Camry, or a Volkswagen Jetta, our technicians have the training, tools, and experience to diagnose electrical issues across a wide range of domestic, Asian, and European makes and models—from classic cars to the latest vehicles on the road. Each manufacturer has unique electrical architectures and diagnostic protocols, and our team stays current with ongoing training to handle them all.
The St. Louis region’s weather puts tremendous stress on your vehicle’s electrical system. Brutal summer heat accelerates car battery degradation and can cause wiring insulation to become brittle and crack. Cold winter mornings demand maximum performance from your battery, alternator, and starter repair components. Add in the humidity and road salt common to the Lemay area, and you have a recipe for corrosion that attacks connectors, grounds, and electrical components throughout your vehicle. Our technicians understand these local factors and know exactly where to look for climate-related failures.
When you bring your vehicle to Fitz’z Automotive Service, you’re working with a family-owned business that has been the trusted dealership alternative in the St. Louis area for over 30 years. We offer the same diagnostic capabilities and technical expertise as the dealer—often at a lower cost—with the personal attention and accountability that only a locally owned shop can provide. Our ASE-certified technicians treat every vehicle as if it were their own, and our long-standing reputation in the community is proof of our commitment to quality auto electrical repair.
Located right here in Lemay, MO, we’re conveniently accessible for drivers throughout the surrounding communities. Whether you’re coming from near Affton, Mehlville, Oakville, or South City St. Louis, our shop is an easy drive. We proudly serve the greater St. Louis metropolitan area and welcome anyone looking for honest, expert electrical diagnostics and repair.
Don’t Just Take Our Word For It!
While our shop calls Lemay home, we proudly serve drivers from Mehlville, Oakville, Affton, Concord, South City St. Louis, and communities throughout South St. Louis County. Customers travel from across the metro area because they trust our expertise and value our honest approach.
Located on South Broadway, our shop is easily accessible from Jefferson Barracks, Lemay Ferry Road, and Interstate 55. Whether you’re a veteran visiting the VA or a local resident heading to Hancock Place, we’re right in the neighborhood and ready to help.
A basic diagnostic scan and battery testing can often be completed within 30 to 60 minutes. However, complex electrical issues involving intermittent faults, short circuits, or multiple system failures may require several hours of detailed circuit testing and wiring harness analysis. We’ll always provide you with a time estimate before we begin and keep you updated throughout the process with our digital inspection reports.
Diagnostic testing costs vary depending on the complexity of the problem. Simple code retrieval and interpretation differs from in-depth circuit testing that requires specialized equipment. At Fitz’z Automotive Service, we’re upfront about our diagnostic fees, and we’ll explain what’s involved before any work begins. The investment in proper diagnostics almost always saves you money compared to the alternative of replacing parts based on guesswork.
Yes—this is one of the greatest strengths of professional electrical diagnostics. Intermittent problems, like dashboard lights that flicker occasionally or a check engine light that comes and goes, often leave traces in your vehicle’s stored fault codes and freeze frame data. Our oscilloscopes can capture signal anomalies in real time, and our experienced technicians know how to simulate operating conditions that trigger intermittent faults. These are the types of problems that frustrate vehicle owners the most, and professional testing is the only reliable way to solve them.
Once we’ve identified the root cause of your electrical issues, we present our findings through our transparent digital inspection platform. You’ll receive a detailed report with photos and a clear explanation of what we found, what needs to be repaired or replaced—whether it’s an alternator replacement, relay replacement, starter repair, or wiring harness repair—and an accurate cost estimate. You make the decision on how to proceed, and we’ll never pressure you into repairs you’re not comfortable with.
Don’t let electrical issues leave you guessing—or stranded. Whether you’re dealing with a dead battery, a persistent check engine light, malfunctioning power windows, mysterious dashboard lights, or any other electrical concern, the team at Fitz’z Automotive Service in Lemay, MO is ready to help. Our ASE-certified technicians will diagnose the problem accurately the first time and provide you with transparent, honest recommendations for repair.
Call us today or visit our shop in Lemay to schedule your auto electrical diagnostic testing. With over 30 years of experience as St. Louis’s trusted, family-owned dealership alternative, you can count on Fitz’z Automotive Service for expert auto electrical repair on all makes—from classic cars to the latest domestic, Asian, and European models. Let us show you why your neighbors in Lemay keep coming back.