TwistedCivic

Ok so i just replaced my radiator on my 1990 civic si HB. got it all filled up and started it up. the engine reaches running temp but the fan never turns on.

smoke starts coming from the cap area.

I check the fuse and its fine, when i filled the rad back up i had the air hole open and closed it when the fluid was running out smoothly.

The fan must of been working before or else my car would of over heated all the time(it would if i was driving for 40 minutes or longer, but the rad was in horrible condition with barely any coils left. I tried putting a screwdriver in the top hose to let any air escape and it still wouldnt turn on.

thanks for any advice

Persia

To be honest man, i have never seen or heard my fan turn on either, as long as you dont over heat you dont need to worry. Just make sure you leave the cap off long enough to bleed it properly and your good.

DTP crew had this discussion in person on this past sunday, and none of us have heard or seen our fans turn on. So your not the only one. I hope this helped.

chris_v2

Everytime I bleed coolant in the shop I hear the fans turn on, so I don't know what you're talking a bout. In real world operation in the winter, the fans will hardly come on, but if you sit there with load on the engine in a garage, they will definitely turn on.

Revv f it for a bit, if it's functioning, the fans will turn on. And once the cabin has full heat, turn OFF the blower, this will help the coolant temp rise up a bit.

MPR

Did the rad in my civic a couple months back. I filled it and bled the air out, put the cap on and before too long, just sitting idling, the fan came on. I made sure it came on.

With my accord, it took a lot longer but it's rad fan also came on. It took me revving it and letting it idle for a good 10 mins + before it came on.

To the OP: Your thermostat maybe stuck open and it's taking it longer to come up to temp... When's the last time it was replaced?

reasonable rock

My fan comes on when I sit with the stereo running or after a good run while sitting at a light. If your fans don't come on at all you may want to check it out. I should mention I am running a B18C with a half-sized rad. OEM rad.
There must be a way to run voltage directly to the fan from the battery. If you can do that, you can confirm that the fan actually works.

D.T.P

Yes, if you feed power directly to the fan, all you confirm is that fan motor is good. Now there is a fan switch which may be failing to turn it on. Hell i've never seen my fan go on, EVER! and im always running cool. I know it works because when my relay went to ****, i was overheating. Swapped the relay, and back to normal.

zeeman

iTrader: (1)

first check that the fan is plugged in (stupid and obvious, I know, but it had to have been unplugged to replace the car)
then check that the fan turns on with 12V applied directly to the fan plug, if it does you know its not the fan itself.
then jump the fan switch plug (located on the back of the engine by the oil filter, it should be a big green plug with 2 wires in it, put a wire in both ends of the plug (jump it) and when you go KOEO (key on, engine off....2 clicks forward) or turn the engine on the fan should turn on immediately, if it does you can eliminate the fan switch (thermoswitch) as the problem.
then check the rad fan relay.
you could also have a problem that lies within the wiring for the fan, fan switch, or relay.