Why won't my Mitsubishi Galant start when it rains?

Short answer: On the 1999–2003 Galant, a no-start in wet weather is usually ignition: cracked spark plug wires leaking spark to the engine, or moisture inside the distributor cap. Owners test the wires by misting them with water in the dark and looking for sparks. A sudden stall with no spark at all can also be the crankshaft position sensor.

Symptom: On rainy or humid mornings, or after a car wash, the engine cranks but won't start, or runs rough. Once it dries out, it's fine.

What to check first

1. Check plug wires in the dark: with the engine running, mist them with water and watch for tiny sparks jumping to metal.
2. Open the distributor cap and look for moisture, cracks or corrosion.
3. Check the cap seal and distributor O-ring.
4. If it died suddenly with no spark, have the crankshaft position sensor tested.

Likely causes

1. Cracked spark plug wires. Leak spark when wet.
2. Moisture in the distributor cap. A bad cap seal or O-ring lets water in.
3. Crankshaft position sensor. Suggested for a sudden highway stall with no spark.

What it usually costs

The threads didn't list prices. Plug wires, a cap and rotor are inexpensive parts; one owner had already replaced the battery and alternator without fixing it.

Is it safe to keep driving?

It usually won't harm the engine, but a car that stalls on the highway is dangerous. Verify with a mechanic.

DIY or shop?

DIY. Wires, cap and rotor are basic jobs. A crank sensor is moderate.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Mitsubishi Galant: 00V299001 (2001-2001 model years, engine and engine cooling); 00V320001 (2001-2001 model years, fuel system, gasoline); 00V339000 (2001-2001 model years, electrical system); 01V069000 (2001-2001 model years, fuel system, gasoline); 02V147000 (2002-2002 model years, electrical system); 03V442000 (2003-2003 model years, fuel system, gasoline); 99V333001 (1999-2000 model years, electrical system). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• NHTSA complaints: 138 keyword-matched complaints for Mitsubishi Galant 1999–2003 (of 799 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-23; keywords: stall, no start, won't start, die, rain, wet). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 2001 Mitsubishi Galant won't start in wet conditions on Car Talk, an owner's car wouldn't start in wet weather even after a new battery and alternator. Members suggested checking the plug wires by spraying water on them in the dark and looking for moisture inside the distributor cap, its seal and the shaft O-ring.
• In 2001 Mitsubishi Galant electrical problem on Car Talk, an owner's car died on the highway and had no spark. Members pointed to the crankshaft position sensor.

Quick tip

If it only acts up when wet, it's almost always ignition. Do the water-mist test before spending money on batteries and alternators.

Vehicle focus: 1999–2003 Mitsubishi Galant with the 2.4L 4-cylinder or 3.0L V6.

Safety / mechanic note

A stall on the highway is dangerous. Verify with a mechanic.