cooling fans not working - Honda Prelude Forum

ECHprelude · 02-04-2003, 10:27 AM

ive tried searching but couldnt find anything on this. when i bought my car (used) my cooling fans werent working. i checked the fuse and relay and both work fine. does the fan run off the termostat? if anyone else knows what it could be, please feel free the suggest something. right now it is just ghetto rigged so they come one when the car is on. so yes the fan does work.

G_Loc · 02-04-2003, 10:31 AM

before you ghetto rigged them, would they come on when you turned on the a/c?

the radiator fan (the bigger one on the right side of the car) is turned on by the radiator fan control module. There are two temperature switches that activate the fan. if either switch or the radiator fan control module is shot, then it wont work.

ECHprelude · 02-04-2003, 12:05 PM

wouldnt come on with the ac either, but i do have the jdm climate control hooked up, dont think that would matter though.

G_Loc · 02-04-2003, 12:20 PM

there's 4 fuses related to the fans. #47 and #45 in the underhood fuse box and #9 and #23 in the panel under the dash. did you check all of them?

if they're all fine, might be the radiator fan control module since you say the fans don't come on when the a/c is on and the relays are fine.

ECHprelude · 02-04-2003, 12:24 PM

yea, checked all those fuses and are of them are good. where is that control module located at?

93h22a · 02-04-2003, 12:39 PM

on the left of the ecu in the passenger floor panel

ECHprelude · 02-04-2003, 01:06 PM

ok, i will "borrow" one from the junkyard tommorrow. see if that solves it. thanks, if not, any other ideas?

X01VTEC · 02-04-2003, 02:26 PM

good luck man, i had this problem after i dropped in the jdm h22a and ecu, and the fans worked perfectly before the swap, and its not like i had to modify anything really, cause my car came with a usdm vtec from the factory, i tried everything tested everything, all relays and fuses were fine. i just ghetto rigged it, put 2 switches in, 1 for each fan. just dont forget to turn on the fan

ECHprelude · 02-04-2003, 04:19 PM

wierd, i cant understand what it would be. hope i dont have to keep it ghetto rigged, i hate that.

X01VTEC · 02-04-2003, 04:20 PM

Quote:

Originally posted by ECHprelude
wierd, i cant understand what it would be. hope i dont have to keep it ghetto rigged, i hate that.

me too, any new suggestions

Forbidden · 02-04-2003, 05:29 PM

My radiator fan never worked in my car, get a Helm or at least borrow one or something, there's a troubleshooting that'll tell you what's wrong.

For me it said "There's a open in the BLU/something wire between the under-hood fusebox and the diode", problem is the wire goes from the fusebox, in the car under the dash, to the other side of the car, back into the engine bay right behind the windshield washer tank.

I tried finding where the problem was last summer but haven't find it yet. I'm planning to disassemble most of the interior next summer to clean everything and make sure everything is tight and doesn't rattle like it does now so I'll probably spend some time finding where the problem is...

G_Loc · 02-04-2003, 05:33 PM

after looking over my helms, it appears that a malfunctioning ECM could also prevent the fans from working.

ECHprelude · 02-04-2003, 07:20 PM

it seems most common with motor swaps so maybe it is a ECM problem. great!

X01VTEC · 02-12-2003, 10:24 AM

Quote:

Originally posted by ECHprelude
it seems most common with motor swaps so maybe it is a ECM problem. great!

i hope thats the problem, and i hope it will fix itself when i get around to installing the aem ems

red92s · 02-12-2003, 01:11 PM

I was playing around under the hood and noticed something wierd. When my car is at normal operating temp (3 bars on temp gauge), but just sitting still, neither fan is on. When I switch the AC on, BOTH fans come on. When AC goes off, so do both fans. It was pretty cold last night, and the car had been sitting for 5 minutes when I did this. . .any thoughts?

G_Loc · 02-12-2003, 01:48 PM

the fans dont work all the time when the temp gauge is at 3 bars. the gauge may be at three bars, but the water temp was probably lower than that needed to turn on the fans.

and the AC turns on both fans.

X01VTEC · 02-12-2003, 05:44 PM

Quote:

Originally posted by G_Loc
and the AC turns on both fans.

in my case the ac button didnt do ****, not sure about everyone else tho

G_Loc · 02-12-2003, 05:51 PM

have you tried getting an extra ECM to see if that is indeed the problem?

X01VTEC · 02-12-2003, 07:57 PM

not yet... when i had this problem a few months ago, everyone that replied seemed to rule out the ecm... i dont really know anyone with a ecu i could swap out to see if that fixes everything. ill just keep using my manual fan switches until i get the wideband up and running then ill see if the aem ems will run the fans

Prelude2War · 02-12-2003, 10:07 PM

Quote:

Originally posted by ECHprelude
ive tried searching but couldnt find anything on this. when i bought my car (used) my cooling fans werent working. i checked the fuse and relay and both work fine. does the fan run off the termostat? if anyone else knows what it could be, please feel free the suggest something. right now it is just ghetto rigged so they come one when the car is on. so yes the fan does work.

sorry