Narao

Hello, I'm new to the forum and wondering if I could get some help. Currently the issue is that my car is overheating relativly easily. Here are the following symptoms and I suspect the car is over heating because the radiator fan is not turning on:

-car overheats after driving only a mile of 2
-the check engine light came on giving error code p0117 stating low voltage to the ECT sensor
-the fan does not turn on when temperature gauge is up 3/4 of the way
-I replaced the thermostat and it still overheats
-there is a small leak in the radiator at the top where the metal folds over the top. I dont suspect this as the problem as it still cycles the radiator fluid.
-I tried installing a new thermoswitch purchased from a local Checkers and that did not fix the problem. (The new thermswitch connector looked a little longer then the one being replaced, so it is possible that it may have been the wrong one.
-I replaced the water pump 6 months ago and it is working
-the radiator fluid heats up and boils quickly (releases steam through cap)
-I've switched relays in the under the hood fuse box just to make sure they are good
-I have not tested the voltage at the fan yet (i currently do not have a voltage meter)

there might be some other things that i couldnt think of at the moment, but any information would help and be much appreciated. this is our only car and puts a cramp in our lives when we dont have it.

Thanks for any posts in advance.

forcefedferio

Welcome to honda-tech, and thank you for a very clear description of your problem instead of half assed broken up ebonics and numbers instead of words.

For your problem, which switch did you replace? On the head or the thermostat housing? The thermostat housing is the fan switch. To check it jump the wires from the back with a paper clip to complete the circuit and power up the fan. If the fan turns on when you do this, you have a bad switch. If it doesn't then most likely a bad fan/motor.

Fix the leak immediately, with a leak you are losing pressure and causing the cooling ability of your car to decrease rapidly. I forget what the measurement is but for every pound of pressure you lose the car heats up so many more degrees.

Try what i told you real quick, and report back.

Narao

wow thanks for the fast reply. alright here come the things i forgot to add:

I did jump the fan and it works so the motor isnt bad.

I switched out the sensor attached at the thermostat housing but the fan never kicked on even when temperatures when in exess of 60%. but then again the connection of the new sensor was longer than the old one and the cable never clicked into place. but i figured that the + and - were still making contact. It may not have been the right sensor.

I do have a new radiator but was trying to fix the fan issue before I put it in. If you think this will be imperative to do before I proceed I'll install it and then get back to you.

forcefedferio

Yes put the new rad in, you won't damage it even if it doesn't fix your problem.

As for the sensor try another one, it sounds like they just simply gave you wrong one. It sucks but we're all human and mistakes happen.

Good luck, check back if you have anymore problems/questions.

95soul

I had the same problem, and Nothing fixed it. My fan wouldnt kick on. I ended up just running a toggle switch setup.

forcefedferio

There was obviously error in your diagnosis, or you got a defective part and failed to re-diagnose.

Narao

Force was right, installing the new radiator helped a ton with cooling. It is running cool right now but i still need to get a hold of a new sensor. luckily its cool weather right now which gives me time to shop around for it. I appreciate the help and ill come back after ive installed the sensor so anyone else with the problem can diagnose it correctly.

Narao

alright, so here we are 5 days later and there is good news. so after replacing the radiator, the car stopped overheating, but i did notice some, for lack of better description, engine 'burbs' and found out that i was having misfires on my 2,3,and 4 spark plugs. So i replaced those and everything is working great. I still have not replaced the thermoswitch but my check engine light has turned off. well see if it kicks back on, but if it dosent does that mean i dont need to replace it? i guess ill find out when i overheat this summer.

kainemazyck

I have the same car. Are both fans supposed to come on, or just one. i know the other comes on with the ac but should it come on when the ac is off and the temperature kicks on the other radiator fan?

endwell17

im having an overheating problem on my 00 civic si. the bypass hose was split. i replaced it but seems to still be running hot. not sure if i got all the air out the system but i ran the car with defrost on and heat up to 8k gauge standed still i turned off the defrost and heat and ran it again. that time the gauge started increasing temp. once i slowed down shifting at 3k car gauge started to decrease. i let the car sit adding coolant when need be but as i hit the throttle some white smoke came out the tail. im wondering if it could be from the extra amount of coolant added in the radiator or if its from the hg. need help!

dnnich

You've probably solved it but your burning coolant. Your plugs will be dusted white in the cylinder or cylinders also. You need a new head gasket. Thats the white smoke.
I'm having a problem with my rad fan. It won't come on. I've checked the relay, the fan motor, the thermal fan switch and fuse all work no check engine light and stays cool as long as I'm not climbing a steep hill.

Scot Aydelotte

Thanks for the feeds on here! I have a 99 Civic EX coupe with an INOP radiator cooling fan too. Unfortunately, I ordered a new cooling fan motor from Honda only to find out that the problem wasn't resolved. I was about to replace the relay then saw the suggestion of using a paper clip at the thermostat switch connector; can engaged - Thank you! So can I replace this switch without removing the thermostat housing?

dnnich

Scot just use a deep socket it comes off easy. 24mm you may need to loosen the hose a little to fit the socket on. You will lose a little coolent but as long as you don't open the system with air you won't lose much. A rag underneath will catch it all during swap.
My problem was a slow leak pinched gasket at the thermostat all good now. Apparently the fan almost never comes on and thats normal as long as your not overheating. I even boiled my switch suspended in water to make sure it works.

civicjeff28

Hey my 99 civic radioator fan won’t turn on I have replaced thermostat and cooling fan switch and still won’t turn on but when I put a paper clip on the connectors of the cooling fan plug it turns on

I need help ‼️