A failing alternator drains your battery overnight, causes dashboard warning lights, and eventually leaves you stranded. For Mukilteo drivers on Mukilteo Speedway and the Boeing Everett commute routes, Tom's B&M Auto performs a complete charging system test before replacing anything — alternator output voltage, ripple voltage, battery condition, and belt tension. We replace what's actually failing, not the first part in the chain.
Complete charging system test: alternator output voltage at idle and under load, ripple voltage test to catch a failing diode pack, battery load test, and belt condition and tension check.
OEM-specification remanufactured alternator installed. Belt and tensioner inspected — a glazed belt on a new alternator causes undercharging immediately. We quote accurately for difficult-access vehicles upfront.
Post-installation charging system test: voltage at idle and under load, ripple voltage verified. Most alternator replacements completed same day.
Seeing battery warning light, dimming headlights, dead battery or car stalling? Your alternator may be failing. Mukilteo drivers trust Tom's B&M Auto — your local mechanic and auto shop an easy drive from Mukilteo on Hwy 99. Our ASE-certified technicians handle alternator testing, replacement and charging system repair for all makes, domestic and foreign. We offer honest car repair with upfront pricing, no hidden fees, and a free multi-point inspection with every visit. Same-day alternator diagnosis — walk-ins welcome — same-day service available for most vehicles. Proudly serving Mukilteo, Snohomish County and surrounding areas since 1985.
Ripple voltage testing catches a failing diode pack inside the alternator before it causes a complete failure. A diode pack that's 30% degraded still charges the battery at idle but drops voltage under load — the condition that causes a 'new' battery to die overnight. We test for it every time.
On vehicles where the alternator is buried — Honda V6 Accords, Subaru EJ engines, some Audi TFSIs — the labor to access it is substantial. We quote that labor accurately upfront based on your specific vehicle, not a generic flat rate. No surprise charges when we get into it.
Alternator output, ripple voltage, battery condition, and belt tension — all tested.
Not discount rebuilt units. Same 24-month/24,000-mile warranty as all our repairs.
Most alternator replacements completed same day. Accurate labor quotes upfront.
Alternator replacement includes full charging system test (output voltage, ripple voltage, battery load test), belt and tensioner inspection, OEM-specification remanufactured alternator installation, and post-installation output verification.
From Tom's B&M Auto - serving Mukilteo and the greater Seattle metro.
Tom's B&M Auto · 17820 Hwy 99, Suite E, Lynnwood · Serving greater Seattle
Also serving: Edmonds, Mountlake Terrace, Shoreline, Mukilteo, Kenmore, Alderwood Manor