radiator fan not working

[vinniez1314]

hey guys, driver side radiator fan not working at all i havent tried checking anything yet..
(prelude bb6)
HeLP! xD overheating after i vtec it

[riruiz_88]

check your fan switch, could be faulty. and just to be safe check the motor of the radiator fan, make sure there is continuity between the 2 cables from the fan.

[vinniez1314]

where is the fan switch and what do you mean by continuity?

[riruiz_88]

sorry man, didnt explain much. fan switch determines what temperature the fan will switch on.
continuity is checking that the motor has a continuous path for current to flow. using a multi meter on continuity setting, then measure across the motor (positive and negative) you should have a reading that beeps at you telling you its good.

[vinniez1314]

mmm so where is it lol

[string]

On the B-series (nfi about H but it's similar most likely) the fan switch is a single wire doodad which lives on the side of the head. Grounds when the sensor gets to the right temperature and completes the circuit for the fan relay to switch on.

Possible faults:
a) Bad wires - the worst fault and least likely. Makes diagnosing problems very difficult. Test by checking continuity between points in the circuit that your wiring diagram says should be connected (such as the fan switch to the relay negative).
b) Dead fan - hook it up to a battery to test.
c) Dead relay - plug in a spare or give it 12V and listen for the clicks.
d) Dead fan switch - ground the wire attached to the switch and see if your fan comes on.

When my radiator fan stopped working, it ended up being the fan switch. Instead of fixing it I hooked up the switch's wire (which runs to the fan relay) to a 3 position switch - 1) ground [fan on], 2) nothing [fan off], 3) back to the [dead] fan switch incase I ever replace it. After a few days of having the manual switch, I left it on 100% of the time (if you plan to turn it off when you're moving I guarantee you will forget to turn it back on when you get to a set of lights).

If you don't know anything about wiring, it's either time to learn (it's not difficult), or you're going to be wasting money on an auto-electrician.

[vinniez1314]

cheers man, so what you have said is the full check? and is there any other possibilities

[riruiz_88]

just take it to a mechanic or auto electrician.

[vinniez1314]

bit low on funds ahah

[riruiz_88]

do you have any mates who are electricians or mates that know mates? ask them to give you a hand

[J_Phongsavan]

i had same problem man. overheating and s***.....i bought a new drivers side fan for 70bucks at honbits wreckers in smithfield,sydney..fixed all problems, i get colder air now..and vtec comes hard all day long.

[Niche14]

so the fan isnt always on? on works at a certain degree the engine is at?

[~Sp33~]

bit low on funds ahah

You've got all the info you need, if you can't work it out then there's not a lot of options shot of a mechanic.

[vinniez1314]

lol jut replaced it xD stole it from my mates radiator

[dos williams]

first step get a multi meter from super cheap..

[vinniez1314]

all fixed man thanx anyway

[JSpec3]

so the fan isnt always on? on works at a certain degree the engine is at?

correct, it isn't supposed to be on all the time, just when it feels it needs to be.

[vinniez1314]

hahaha problem is solved! dont worry about this thread lol

[JSpec3]

I know man, just helping that other guy out, nobody answered his question.

[xhilr8]

Found out today that I have a dead fan switch. While I'm waiting to get the part in, is it ok to just short out the fan switch connector so that the radiator fan is on 100% of the time?
Also when replacing the fan switch, will I need to drain all the collant fluid out of the system first?

[~Sp33~]

Keeping the fan on 100% of the time is fine as a short term solution. It wont damage anything, though the engine may run slightly colder than usual. You'll have to drain the coolant too.

[xhilr8]

I took the radiator fan switch out today and tested it and it was actually working fine. I boiled some water, suspended the probe above it and when the water was reaching its boiling point, the switch activated. So now I'm a little confused as to why my radiator fan never turns on?? Is it beacause the weather is cold at the moment? I don't get overheating issues, but I've only had the car for about 3 weeks.

I leave the car to idle for over 10mins and the engine gets warm, but my temp gauge reads "normal" and fan doesn't turn on (despite the service manual saying the fan should turn on at least twice in the 10min span).

I've tested the fan by hooking up power to it and it spins, I've tested the relays and all working ok. Fuses are all ok as well. If I unplug the radiator fan switch and short out the connector, the fan turns on so I thought it was the switch problem, but turns its not? Where to go from here....

[JSpec3]

the fan will only turn on if it detects your car getting too hot.

[xhilr8]

the fan will only turn on if it detects your car getting too hot.

Yea I know that..it turns on when it detects temps of 91-95 degrees celcius. But my question is how long does it take for the coolant to reach those temps under normal idling and air temps we are experiencing lately (approx 14 degrees air temp). I thought that idling the car for 10mins would cause the fan switch to turn on. Perhaps I should rev the car to 3000rpm and hold it there to bring the heat up more?

[~Sp33~]

Yea I know that..it turns on when it detects temps of 91-95 degrees celcius. But my question is how long does it take for the coolant to reach those temps under normal idling and air temps we are experiencing lately (approx 14 degrees air temp). I thought that idling the car for 10mins would cause the fan switch to turn on. Perhaps I should rev the car to 3000rpm and hold it there to bring the heat up more?

The fan will turn on with the car's idling.

Have you tested for power to the switch? If there's power to the switch, and the switch works then the fan will come on.

[xhilr8]

OK I finally fixed the problem although I don't even know what I did to fix it. I just took out the fan switch again and gave it a real good clean (there seemed to be some sort of calcium buildup on the probe)..so I used some vinegar and gave it a good scrub. Then gave the electrical contacts a squirt with contact cleaner, let it dry and re-assembled. It took quite a while for the fan to turn on but it did (around 15-20mins of idling).