Hey guys first time posting here. I tried searching but couldnt anything on my issue. This is for a honda civic 2000 ex. My radiator fan has not been turning on so I unplugged the coolant temperature switch and tried placing a paper clip in it. I turned my car on and the radiator fan started spinning. I drove around a bit and checked under the hood a few times and every time the fan was working. So I bought a new coolant temperature switch and replaced it with the old one, took the paper clip out the connector and plugged it into the new switch. I start my car up but now with the new switch the fan wont turn on. I drove around a bit to try to heat my car up but the fan still wont turn on. Any ideas on why the new switch wont work?

 

You have a wiring issue with the plug most likely,

Copied from 1992BB2,

If the fan runs when you jump the connector for the ECT switch, then that can mean three things:

1. The switch is no longer "switching" and is faulty.

2. The switch is not getting hot enough to switch on. (Which could be a clog in the coolant lines somewhere, or maybe you just aren't getting the car hot enough to engage it and it works fine.)

3. The connector that plugs into the switch isn't making full contact with one of the 2 pins.

To rule out the first two, take your multi-meter (If you don't have one, HF has cheap ones that will work just fine for this), and set it to the continuity function. While leaving the switch still installed into the housing, connect one cable of the meter to one pin on the switch, and the other cable of the meter to the other pin on the switch. When it reaches the proper temperature that your fan should kick on at, your meter should beep. If it beeps, then it's number 3. If it doesn't beep, it's either 1 or 2.

Hope this helps.

Also try bleeding the radiator in case there is air in the system

 

Thanks for the help Ill give that a try

 

Im going to order a multimeter on amazon whats the lowest $ you would go? Im certain its number 3 so if it ends up being that how could I resolve that issue?

 

Easy just buy a brand new pig tail plug, just make sure to crimp or match the wires in the same orientation that its in the original plug so you dont swap the power and ground.

RADIATOR FAN SWITCH CONNECTOR HARNESS PLUG PIGTAIL FOR HONDA CR-V ACURA CIVIC | eBay

 

Before you go spending money, how high is the Temp gauge getting? It take FOREVER for the engine to warm up to the point that the fan will turn on. Drivning it around a bit will keep the coolant too cool to turn the fan on. Start the car and let it sit until the temo gauge is at 3/4 high if the fan doesnt turn on then, then start looking at why.

 

^^^^ This is what I was going to say.

Is your car overheating, if it is not, then most likely everything is fine. On a warm day it takes 20 minutes idling with some revving to get the fan to kick on without moving. When moving, especially in winter, the fan virtually never kicks on.

 

Thanks for all the input guys. It turns out that my fan does turn on and like some of you said my system just wasnt getting hot enough. But now I have a bigger problem, my radiator is leaking from the top with coolant spraying all over that area when I drive highway speeds. Im also seeing a bit of what looks like gas and oil in the coolant. I dont really have signs of a blown head gasket, no overheating, no milky oil or excessive white smoke from the tail pipe but I went ahead anyways and just flushed and used blue devil head gasket sealer so we'll see how that goes. Do you guys think I should just replace my radiator or try to seal the leak somehow?

 

replace the radiator, its cheaper and easier than waiting and then having to do the headgasket

 

So I replaced my radiator with a new one and turns out my old one had a 3in crack in the plastic. No more leaking now from what I can see but now my radiator smokes constantly except for when I have my heater on. I dont mind having the heater on all the time being that its still winter but when summer time comes theres just no way. Man this car is just one problem after another.

 

If the rad is brand new, exchange it for another. Pin hole rad is not going to serve you well and there should be a 30 day exchange policy at the bare minimum, especially new.

 

Check the relay in the under hood fuse block.

If you remove it, note where the two large copper colored male connectors go into the fuse block relay socket. Put you paper clip in there , that is basically completing the circuit and mimicking a relay close contact. The fan should spin with the key on.
the switch that's in your radiator for the coolant sensing. Basically grounds that relays coil out which causes the relay to pull the switch contacts closed in the relay. By using your paper clip for the Relay with plug in you're bypassing the coolant switch and powering the fan directly. If it doesn't spin up from that you need to check if you're actually getting positive current from the relay to the plug at the fan from the fuse block

 

do you have a puddle of antifreeze under the car? If not then it is just the spill over steaming off. When you turn on the heater it cools the antifreeze and the radiator cools down. IF you are worried about it, go to Autozone and borrow a coolant system test kit. Pressurize the system. It should be able to hold something like 14psi. If lower then that, you have a problem