Auto electrical diagnosis and repair in Winthrop Harbor
Pfeiffer Auto Clinic diagnoses and repairs vehicle electrical systems in Winthrop Harbor, Illinois: alternators and charging systems, starters, wiring and connectors, grounds, fuses and relays, parasitic battery drains, power accessories, and lighting circuits. Electrical faults can look like other failures, including harsh shifting and warning lights, so we test the circuit before replacing parts.
What we test and repair
- Alternator output and charging voltage
- Starter draw and starting circuits
- Parasitic drains that empty the battery overnight
- Grounds, connectors, fuses, and relays
- Power windows, locks, mirrors, and seats
- Lighting circuits and headlights and bulbs
- Upfit wiring on work vans and trucks
Batteries
Battery testing and replacement have their own page: car battery replacement.
Electrical problems affect shifting too
Modern transmissions depend on sensors and solenoids. Low voltage or a bad ground can cause harsh shifts and warning lights that look like transmission failure. We check the electrical basics during every transmission diagnosis.
Salt and corrosion
Road salt works its way into connectors and grounds under the vehicle. Many intermittent electrical problems on lakefront vehicles trace back to a green, corroded connection. Cleaning and sealing it fixes the cause.
Frequently asked questions
Is it my battery or my alternator?
If the vehicle starts after a jump and then dies, or the battery light comes on while driving, the charging system is a suspect. Testing both takes the guesswork out.
What drains a battery overnight?
Common causes are a module that stays awake, a stuck relay, an aftermarket accessory, or a light left on. We test the draw to find it.
Can you fix wiring on my work van?
Yes. We diagnose and repair wiring, including upfit circuits for lights, inverters, and accessories on work vans and trucks.