Toyota Repair: Radiator Fan Motors, radiator coolant, replacement radiator

Question
QUESTION: Hi Ted,

I have a 1995 Toyota Camry 4 cyl with AC. Ted, I don't think the two electric fans that cool the radiator are running. All the fan wiring plugs are connected.

I replaced the radiator yesterday because it had a leak. The radiator I replaced yesterday was an aftermarket one I installed in July of 2009 but was leaking already.

After installing the replacement radiator yesterday, I was running the engine with the cap off the radiator till the engine was up to normal operation temperature and the bubbles stopped flowing and both hoses were hot. I thought the fans should have come on but they did not come on to cool the radiator.

While I was bleeding the radiator some coolant from the radiator did overflow the radiator and ran down onto the fan motor on the passenger's side of the car. Is that fan motor water proof? Could a fuse have blown? I searched around in several repair manuals to look for a location unsuccessfully. Where would a fuse for the fans be located if that could be the problem?

I also noticed another problem after driving the car to warm up the transmission to check that fluid level. You know the rubber hose that runs from the overflow plastic jug to the neck of the radiator. Coolant was leaking from the rubber hose that connects to the radiator neck under the cap. I plan to buy a new quarter inch ID hose today and new clamps. I am guessing while I was driving more coolant may have run down on that fan motor.

So I am at a loss why both fans are not working?

Thanks Ted for pondering this issue.

Sincerely,

Mike


ANSWER: Both fans should turn on when the A/C is engaged, if they don't come on then it may be a relay problem but if they do it is probably a temp sensor for the cooling fan, the sensor is located on the bottom of the radiator, disconnecting the sensor should make the main cooling fan turn on, if this happens replace the sensor.

---------- FOLLOW-UP ----------

QUESTION: Hi Ted,

I live in Pennsylvania where the day time highs are in the 20s or 30s.

When I turn on the AC, the two fans do run together for a short time then shut off when the compressor shuts off. Then I turned off the AC. Next I unplugged the temp sensor connector as you suggested from the bottom of the radiator. Both the cooling and AC fans came on immediately even with a cold engine.

Two other pieces of information to share about this problem that I didn’t include last time are these.

First:
Two weeks ago a mechanic replaced the oil pump o-ring, seals for oil pump, crank, and cam as well as put on new timing belt and pulleys and replaced the valve cover gasket. Is there a chance he damaged a part of the radiator fan circuit in those repairs which would cause the cooling fan not to work?

Second:
In the car when I turn the heater setting on the dash of the passenger compartment to the warmest temp and then turn the fan speed to low, the fan runs noticeably slower for the heater. I can barely hear it. Seems like its blowing less air into the passenger compartment too. Whether the car is hot or cold the fan runs noticeably slow. Not good in freezing cold Pennsylvania! When I move the fan to the next speed setting, it still runs noticeably slower. The third setting is not really noticeably slower and the fast speed seems more normal. Is this passenger compartment related to the radiator fan issue??

I checked the resistance of the connector on the wiring to the temp sensor with the engine and key off. The ohms were about 46. I could not get the probes of the multimeter up onto the terminals of the sensor to check its resistance.

There is no drain on the aftermarket radiator I installed. Draining thru the lower radiator hose or thru the temp sensor hole causes the clean fluid to get dirty as hit contacts the frame of the car etc before hitting the bucket. Before I drain the radiator again, is there something else I should check first?

I hope to go on a 154 mile trip farther north in Pennsylvania to visit parents over Christmas. If the fan isn’t working by then could I still drive the car 154 miles in 20 and 30 degree weather without overheating the engine?

Thank you Ted for your assistance!

I really appreciate all you do to empower me!

Sincerely,

Mike

Answer
Since the fans do run when disconnecting the connector it means that all the wiring and the relays are ok, what needs to be done is to make sure the engine comes to operating temperature to at least 1/2 on the gauge, if it does then try replacing the temp switch. The inside fan has nothing to do with the cooling fans it may be a bad fan resistor that controls the fan speeds.
In this cold weather it doesn't matter if the cooling fans come on especially at highway speeds when there is plenty of airflow through the radiator and it should be ok except for prolonged idling periods.