Cooling fans not working 1999 chevy ventura

As before, the short answer to your main question is no. A quick way to check the wiring would be to pull the relays and jump the battery power terminal to the trigger terminal, but you would have to have a wiring diagram to know which is which. If the fan came on, you would know that at least that part of the wiring harness was OK.

Sounds as if,the cavalier,may have an internal blown head gasket.

The fuses are located in the fuse box under the hood, but could be the fan motor too, check if you have power at the motor

cooling fan relay could be bad,check relay by making a fuse jumper wire.look at the relay control circuits on relay look for control circuits terminal number 85 and terminal 86 hook fuse jumper wire terminal 85 on relay to good ground and take terminal 86 on relay hook up a jumper wire touch battery positive terminal relay should click if not, relay bad.

The fan is powered by multiple control points. The first thing to check is fuse for cooling fans. If fuse is good then check the fan relay(s). After making sure those 2 items are good then check temperature sensor on the engine. Those are the main items that control cooling fans. Some vehicles are also controlled through the ECM.

CHECK MODE RELAY IF BOTH RELAYS GOOD YOU CAN CHECK RELAY BY REMOVING IT FROM FUSE BOX HOOK RELAY TERMINAL 85 TO BATTERY POSITIVE AND GROUND TERMINAL 86 IF CLICKS RELAY GOOD. IF RELAY GETTING POWER GOOD AND THE 30 AMP COOLING FAN FUSE OKAY.EITHER THERE IS A SHORT IN COOLING FAN WIRING OR THE PCM HAS FAILED.THE PCM HAS LOST OR COMMAND RUN CIRCUIT IN PCM SHORTED OUT DUE TO PCM FAILURE.LET DEALERSHIP OR GARAGE USE DIAGNOSTIC EQUIPMENT TO ACTIVATE THE PCM SEE IF IT HAS FAILED.DONT SPEND MONEY ON NEW PCM COULD BE SHORT IN THE WIRING CIRCUIT

COOLING FANS NOT RUNNING

It is normal for the A/C air to warm up a little when stopped. Less airflow thru the condensor. It is normal for the engine temperature gage to rise up to about the 80% mark on its scale before the cooling fan kicks on. The gage will also show about the same reading on the first start of the day, until the thermostat opens.

If the fan(s) are not working properly the A/C air and engine temperature will rise. If you have a belt driven clutch fan, the clutch may be worn out. All cooling fans kinda sound like miniature jet engines when its hot out, more so when the A/C is on. Replacing the clutch is all you can do for a belt driven fan. Electric fans are more complicated....
Check all main power electrical connections first.... Electric Fan(s) not working, Checking the fan(s), relay, fuse and engine temperature sensor's.
Verify that the fans work by unplugging them and run jumper wires to the fan(s) from the battery. If they run, your problem lies elsewhere. If either does not run, it's the motor.
Next thing to check is for power at the fan connectors. You have to be cautious doing this because the engine needs to be running and warm if not almost hot, and the A/C also needs to be on. (Both must be on and running for the duration of this checklist.) The A/C fan is on the passenger side and should come on almost the instant the A/C is turned on. It is also the secondary engine cooling fan and should cycle on and off in relation to engine temperature. Use a test light to probe the two wires on each fan. If you find power the fan motor(s) is/are probably bad. If there is no power to fans, roll up your sleeves!

The temperature switch is usually located above the oil filter. If the dash gage is working, its probably OK. Next is the Fan Control Temperature Sensor, located IN or CLOSE to the thermostat housing. You will find out if it is working later is this checklist. I just wanted you to know where it is. Next is the relays and fuse's. Usually located in the engine compartment on the passenger side power distribution box. You will need to remove anything over the cover to open it. If the fuses are OK, tap on the relays or pull them out and push back in. If the fans are still not running, pull a relay and probe the socket terminals for power. Two or three of the terminals should have power, usually criss-cross from each other. Two are hot battery power, and the third is the "signal" voltage which triggers the relay to send 12V battery power to the fan. This signal voltage comes from the sensor at the thermostat. If only two terminal's have power, then I would replace the thermostat sensor if not both sensors.

Hope this is clear as mud! and helps! Please let me know what you find.

I would find the circuit breaker relay that supplies power to whichever power distribution box that contains the cooling fan relays. If the box has power, then you may want to consider the following: I feel that if you find out why the fans quit working, then you may also have solved the front turn signal issue.

Electric Fan(s) not working, Checking the fan(s), relay, fuse and engine temperature sensor's.
Verify that the fans work by unplugging them and run jumper wires to the fan(s) from the battery. If they run, your problem lies elsewhere. If either does not run, it's the motor.
Next thing to check is for power at the fan connectors. You have to be cautious doing this because the engine needs to be running and warm if not almost hot, and the A/C also needs to be on. (Both must be on and running for the duration of this checklist.) The A/C fan is on the passenger side and should come on almost the instant the A/C is turned on. It is also the secondary engine cooling fan and should cycle on and off in relation to engine temperature, (If the A/C is OFF). Use a test light to probe the two wires on each fan. If you find power, the fan motor(s) is/are probably bad. If there is no power to fans, roll up your sleeves!

The temperature switch is usually located above the oil filter. If the dash gage is working, its probably OK. Next is the Fan Control Temperature Sensor, located IN or CLOSE to the thermostat housing. You will find out if it is working later is this checklist. I just wanted you to know where it is. Next is the relays and fuse's. Usually located in the engine compartment on the passenger side power distribution box. You will need to remove anything over the cover to open it. If the fuses are OK, tap on the relays or pull them out and push back in. If the fans are still not running, pull a relay and probe the socket terminals for power. Two of the terminals should have power, usually criss-cross from each other. One hot terminal is battery power, and the other is the "signal" voltage which triggers the relay to send 12V battery power to the fan. This signal voltage comes from the sensor at the thermostat. If only one terminal has power, then I would replace the sensor at the thermostat, if not both sensors.

CHECK COOLING FAN FUSE AND RELAY.IF BOTH GOOD SCAN CAR TO CHECK COOLANT TEMPERATURE SENSOR FAULT CODE.THE PCM AND COOLANT TEMP. SENSOR IS WHAT CAUSE FAN TO RUN AT CERTAIN TEMPERATURE.IF ALL IS GOOD.HOT WIRE COOLING FAN USING JUMPER WIRES TO BATTERY.IF FAN DONT RUN REPLACE FAN MOTOR.IF FAN RUNS YOU HAVE SHORT OR BROKE WIRE IN THE COOLING FAN ELECTRICAL CONNECTOR.

OK here we go you will need a test light for the following tests, i will try to be as descriptive as possible so lets get started

fist start the engine and turn on the a/c that should command the fan on.
right front engine compartment next to the battery is the power distribution center pop off the top, ground your test light to the negative battery terminal and find fuse number 10 it is a 40 amp fuse check both sides of this fuse with your test light, if you have power on both sides of the fuse than we shall go further.

unplug the connector from the cooling fan, there should be two wires in the plug one is dark green and the other is black with a pink tracer, with your test lite grounded to the negative battery terminal check the dark green wire for power, if there is power there than move your test light ground clamp to the battery positive terminal and test the black wire for ground,
if testing the black wire made the test light shine than the ground circuit is good, if it did not than check you ground connection behind the right headlight.
when testing the dark green wire, if the dark green wire made the test light shine and the ground circuit is good than you simply have a bad coolant fan motor.

I suspect you were not getting power to the fan motor so you will need to take a look at the radiator fan relay, this is a special solid state relay mounted to the inside of radiator core support on the right side down behind the bumper.

here you will find a single plug with 4 wires in it

black = ground
dark blue / pink = relay controll from pcm
dark green = output to radiator cooling fan
gray = battery power from fuse # 10 in pdc

unplug the relay ground your test light to the battery negative terminal, with the engine running and a/c turned on check the gray wire the test light, it should turn on if not recheck fuses.

move your test light to the battery posistive terminal and test the dark blue / pink wire, if the test light turns on than you have a bad radiator fan relay, you can pick one up at your local parts store for about $85.00 just make sure you get a high quality one the cheap ones have a hard time with the amprege consumption of that fan.

good luck

wesley [email protected]