Buy Lexus IS250 Radiator Fans

Quick Summary

Quick Summary

The Lexus IS250 uses a twin electric radiator-and-condenser fan assembly to pull air through the radiator (and A/C condenser) whenever the engine, coolant, or A/C system calls for extra cooling. Two 40-amp "FAN 1" and "FAN 2" fuses plus three relays feed the brush-type motors, giving low- and high-speed operation that the engine computer or A/C amplifier controls. Proper airflow keeps the aluminum V6 at its normal 190 °F range, prevents overheating at idle, and helps the cabin heater and air-conditioner work right. A well-kept fan assembly also protects nearby parts such as the water pump and head-gaskets from heat stress.

What It Does

What It Does

The cooling, radiator, or engine fan (all names for the same part) acts like a big household blower that pulls fresh air through the radiator's fins. This air removes heat the coolant picked up inside the engine. Without that steady breeze the coolant would boil, the oil would thin, and the engine could seize. Electric fans engage only when needed, so they save fuel compared with old belt-driven fans. (Wikipedia)

How It Works

How It Works

• A coolant sensor tells the engine computer the temperature.
• If coolant or A/C pressure is high, the computer grounds one, two, or three fan relays.
• Power flows through the FAN 1 and FAN 2 40-amp maxi-fuses in the under-hood fuse box. (Fuse Box)
• At low load the fans spin slowly; at higher temps both motors jump to high speed. Two-speed electric fans are common on modern cars because they move plenty of air at low road speed but draw less current most of the time. (MotorTrend)

Signs of Trouble

Signs of Trouble

• Temperature gauge creeps past the middle when sitting in traffic.
• The fan never starts-or it runs at full blast even with a cold engine. (MotorTrend)
• Rumbling or clicking noise from the shroud (loose fan screws were a known issue).
• Blown 40 A FAN fuse or melted relay socket.
• A/C warm at idle but cold while driving.

Common Causes

Common Causes

← scroll table horizontally →

Diagnosis Tips

Diagnosis Tips

1. Check coolant level first; low coolant keeps the sensor from reading hot coolant. (StartMyCar)
2. Verify the 40 A FAN 1 & FAN 2 fuses in Engine Fuse Box #1. (Fuse Box)
3. Swap identical relays to rule out a sticking contact.
4. Command the fans with a scan-tool or by switching the A/C on; both fans should spin at once.
5. For a no-spin motor, apply 12 V directly to its connector to confirm the motor is bad.

Replacement Outline

Replacement Outline

Skill: Intermediate DIY
Time: 90 minutes (per Lexus campaign guide)

1. Disconnect battery negative.
2. Remove top radiator cover and air-inlet snorkel.
3. Unplug both fan motor connectors; release wiring loom clips.
4. Unbolt the plastic shroud (four 10 mm bolts).
5. Lift the whole electric fan assembly upward, clearing the lower tabs.
6. Transfer rubber isolators to the new shroud.
7. Set the new assembly, tighten to 62 in-lb (7 N·m).
8. Refill any lost coolant; bleed air with heater on full hot until bubbles stop. (Reddit)

Compatibility

Compatibility

The dual-fan module fits 2006-2013 IS250 rear-wheel- and all-wheel-drive models as well as the closely related IS350; the IS F uses a similar layout but different motor wattage, so part numbers differ. Always match the shroud shape, number of blades, and connector pin count. (CarComplaints.com)

Maintenance Advice

Maintenance Advice

• Blow out leaves and bugs from the radiator fins every oil change to keep airflow high. (StartMyCar)
• Replace coolant every 50 000 mi or 5 yrs; fresh coolant protects the fan temperature sensor from deposits. (Popular Mechanics)
• Listen for new noises when the A/C cycles-catching a loose screw early can save the motor.

Safety & Performance

Safety & Performance

Running hot thins engine oil and may warp heads. A healthy fan also stabilizes intake-air temperature, which helps maintain factory horsepower. An electric fan removes belt drag at highway speed, freeing a small but measurable amount of power and fuel economy. (MotorTrend)

Environmental Notes

Environmental Notes

Efficient cooling lets the catalytic converters stay at the right temperature, keeping emissions low. Electric fans draw power only when needed, trimming fuel use and CO₂ output compared with always-on mechanical fans. (Wikipedia)

Fuse & Relay Map

Fuse & Relay Map

• FAN 1 Fuse (40 A) - slot 24, Engine Fuse Box #1
• FAN 2 Fuse (40 A) - slot 25, same box
• Fan Relays - Fan No. 1, No. 2, and No. 3 in Engine Room Relay Block No. 2, left front of bay. (Fuse Box)
  A blown fuse or melted socket points to a seized motor or shorted harness.

Service Campaigns

Service Campaigns

Lexus issued Limited Service Campaign LSC ELE covering 2008-2012 models because loose fan-motor screws could damage the blades and let coolant temperature climb. Dealers inspected screw torque and, if needed, replaced the whole assembly at no cost until Nov 30 2017. (CarComplaints.com)

Frequently Asked Questions

Q: What does the fan do at highway speed?
A: Above roughly 35 mph the natural airflow is enough, so the computer often shuts the electric blower off to save power. (MotorTrend)

Q: Can I drive with a broken fan?
A: Only briefly and only at steady road speed; slow traffic or drive-thru lines will overheat the engine within minutes. (StartMyCar)

Q: Why do two fans run when I turn on the A/C?
A: The A/C condenser sits in front of the radiator and needs its own airflow; both fans switch to low speed whenever the compressor is on. (MotorTrend)

Q: My fan never shuts off-what now?
A: Check for a stuck relay, shorted pressure switch, or an engine computer that has set a fault and gone into fail-safe. (CarComplaints.com)

Q: Are pusher fans better than puller fans?
A: Puller (behind-the-radiator) fans like the factory IS250 design move air more efficiently and avoid blocking incoming air. (MotorTrend)

Q: What size fuse should I use?
A: Always replace with the same 40-amp "J-case" fuse to avoid wire damage. (Fuse Box)

Q: Do I need special coolant?
A: Use pink Toyota Super Long Life coolant or an equivalent that meets the same ASTM specs; mixing colors can reduce corrosion protection. (StartMyCar)

Q: How often do fan motors fail?
A: Many last past 150 000 mi, but dust, brush wear, and heat shorten life. Listen for squeals or slow spin-up. (MotorTrend)

Q: I hear a rattle when the fan starts-safe to ignore?
A: No. Loose screws can let blades hit the shroud and shatter, a condition covered by the LSC ELE bulletin.

Q: Does an upgraded fan free horsepower?
A: Electric puller fans already reduce drag compared with belt fans; gains are small but real at higher RPMs. (MotorTrend)

Helpful Links (open in new tab):

• NHTSA Limited Service Campaign PDF
• Fuse-box diagram with fan fuse locations
• Overheating guide for IS 250 owners
• Technical Service Bulletin list showing fan screw issue
• Electric fan basics and two-speed operation explained