napa2u

1994 honda accord has two fans. the drivers side will not turn off even if the engine cold. had to pull the fuse. when i put the fuse back in the fan starts running and does not shut off. the next morning after a cold night, installed the fuse and the fan came on continuously. Any thoughts.

barry

PyroProblem

Stuck relay.

napa2u

Where is the relay actually located? and do you remove and replace ?

ty Barry

PyroProblem

Should be in the under hood relay box. Without going into wiring checks for proper diagnosis, just swap it with another relay and see if Thats the culprit.

Before you pull it, give it a few generous taps and see if it will "unstick". If it does, more evidence of a bad relay.

napa2u

Thanks

holmesnmanny

Your fan timer/control unit is bad.

HondaPartsHero

Overheating - Troubleshooting Honda's Cooling System

Proper operation: A number of Honda/Acura with an advance cooling system employ a fan timer system to offset the fragile aluminum head. The timer allows the fan to know when and how long the fan should operate. By switching the ignition off and the coolant temperature exceeds the boiling point the radiator fan will kick in. (However, both the condenser fan and the cooling fan will run when the A/C is on at any temperature.) The fan timer should run for no more than 15 minutes (or much less on some cars) if the engine temp is over 223F. If it is running greater than 15 minutes, or the fan going on/off randomly while the ignition is on or off then either the fan timer is bad, the fan relay, or perhaps there's a bad connection somewhere. If the fan timer system fail to turn on the fan, serious damage to the head and head gasket could occur some time in the future. If the fan runs every time you turn off the engine, you've probably plug the switch to the wrong sensor, the cooling system has poor coolant circulation, you're driving in a hilly terrain or it was just a hot day.


Problem: The fan runs continuously (longer than 19-minutes) when the key is removed. The symptom is a dead battery. The fan turns off only when the ignition is turn ON (not off, correction) and while the high temperature thermoswitch (108 degrees) is checked out okay then 90% chance the fan timer is bad. Usually happens to the 90-93 Accords. If the fan runs after removing the key on a cold engine then something could be wrong with the high temputure thermoswitch. After the key is removed and the engine cold and by plugging the high temperature thermoswitch back in and the fan runs then the high temperature thermoswitch is bad. (error in this section is spotted by a honda-tech.com member)

Solution: The reasonable solution is to replace the timer control unit. Before replacing the unit it would be prudent to troubleshoot. When the fan does not turn off after 15 minutes swap the cooling fan relays in the engine fuse compartment with another identical relay. If the fan refuses to turn off replace the fan timer unit.

Replacement: Remove the access panel on the driver's kick panel and search for a box way in there the size of two cigarette packs with 8-terminals. The 86-89 Accord fan timer unit is located under the passenger seat. Unbolt the unit and swap it with a new one.

No IMAGES DISPLAYED - Please enable refferers to see images. 9093accordtimer location
Note: the fan timer location is a bit more to the right compared to this image. It's right next to the main relay like this image (as seen the main relay removal page.)

napa2u

beautiful,

illl let you know

napa2u

Where is the fan timer control on the 84 Honda Accord?
Also the cooling fan fuse link was bad. Not sure if that makes a difference. I only find a cooling fan relay and a condenser fan fuse link. The car hasn't been run in a week and I put the condenser fan fuse in and the fan goes on right away on a cold soaked engine

napa2u

Also when does the radiator fan kick on. It's not running on start to warm up

slowcivic2k

Bad thermoswitch is another cause. If this switch has failed shut, the fan will never turn off. Reinstall the fuse, disconnect the thermoswitch connector. If the fan stops, the switch has failed closed, and needs to be replaced. If the fail continues to run, you have a short to ground before the thermoswitch input wire, or the module itself has failed.

This switch needs to be checked before condemning the fan control module, as this switch is an input that controls the fan relay output. Very common on older (pre-1995) vehicles of all makes.

If you are unsure where the thermoswitch is, it is commonly located on the thermostat hot side. If you cannot locate it, use a factory service manual.

napa2u

Thank you . I will try what you say .

PyroProblem

Even with ignition off? Don't they usually fail in the open position causing the fans to never come on?

OP, this is a 94 accord, not an 84 right? I saw somewhere both were listed.

napa2u

its a 1994 Honda Accord

slowcivic2k

I've repaired a lot of pre-1995 vehicles with the cooling fan stuck on because of a bad thermoswitch. Ford's, GM's mostly, but any vehicle of this vintage that has a hard wired control for the fan can have this problem. The fan power supply is relay switched. If this problem just occurred out of nowhere it is more likely that the thermoswitch failed rather than the relay being "stuck on". Relays rarely fail in the shut position, because the return element is spring loaded. It is, however, very likely for a relay to fail in the open position and not function at all due to contact wear and corrosion.

You need to verify that the thermoswitch is not grounding when it shouldn't be. If it is sending this false input, the fan will always come on because the switch inputs an over-temp signal to the module, causing it to ground the fan relay control circuit and power the fan. If this sensor is functioning correctly and the fan still comes on, troubleshoot the relay control coil circuit. This can be done simply by pulling the fan relay and "feeling" the relay click on and off as you install and remove it. The means the control side of the circuit is being commanded on. This circuit is either shorted to battery voltage, or the module itself is putting out battery voltage to this relay at the wrong time (IE defective module). This module receives battery voltage at all times, so the fan will come on anytime the logic dictates. It is, also possible, since the PCM can bypass the thermoswitch, that the PCM is grounding the fan, indicating a defective PCM.

Since I am feeling productive at the moment, here is a schematic of the circuit. I suggest you locate and purchase a manual for your vehicle as well. I can't post the entire internet for you:

napa2u

You gone beyond the call of duty. I truly thank you for your input. Good thing I'm mechanically inclined and understand schematics ( airline pilot) because you got pretty technical. I will work on it this weekend and I will let you know what I find.

Kindly regards,

Barry