Alright, I have 94 Civic with the stock d15b7. I replaced the Thermostat a couple of days ago and drained and filled it with new coolant, since I overheated while I was a redlight. After replacing the T-stat and bleeding the coolant system. I noticed my fan would not cut on at all, so I went out and bought a new Fan switch, still nothing. So, I went back to autozone to exchange for another Fan switch since it might be defected, still nothing.

The car does not overheat at all, the coolant is still green, both upper and lower hose gets hot. When I jump the fan it kicks on. Any ideas on what it could be?

Also on the way home I noticed I was leaking coolant from the overflow reservoir, im assuming its because of the fan not kicking on. The temp guage was still a little bit under half the whole way home. Not overheating once.

TIA.

 

I want to fix this the right way, without rigging a stupid switch.

stupid fan.

 

so you're fan won't come on while you're driving it? well it may just be that you're car is keeping itself cool WITHOUT the fan. the fan will only come on at the temperature it NEEDS. so if your car doesn't reach that temperature, then no fan. i think the needle shouldshow like 1/3 of the way up. thats the usual spot that it should show for the fan to come on.

or the relay is weird lol idk

 

Yeah, its not coming on at all. Even at idle. Im sure its not normal because the overflow can is filled with coolant and is leaking out.

 

uhhh your thermostat is opening right? does the bottom radiator hose get hot? it sounds like the thermostat may be STICKING. this will cause the pressure to build up in the cooling system, thus making your overflow can leak out.

*is the thermostat instaled correctly with a new gasket?

 

yes, the lower hose and upper hose gets hot after driving around towm. It takes a little bit longer for the lower hose to warm up, if im just waiting for it to while its idleing.

And thermostat is installed correctly.

 

oh ok good. well good luck. *edit. not a girl HAHA!

 

did you bleed all the air out?

did you check the fuse? i know you said the fan cuts on when you jump it but idk exactly how you are jumping it or how the wiring is setup.

 

~

 

TIA:

Thanks
In
Advance

 

LOL!!! I fail. Tia was one of my EX girlfriends name too.

 

Yes, I've bleed it a lot of times now went through 3 coolant jugs. Tried both the radiator cap off and bleed valve way.

The wiring is still the same old stock harness. And the way I test the fan to see if it work, I unplug the plug from the fan switch at the tstat housing and stick a paper clip on both connectors. All fuses under the hood and dash is good.

 

Try replacing the fan relay. if that doesnt work sounds like the fan motor went out.

With coolant coming out of the resi, if it continues to do this after you get the fan to work, you might have a blown headgasket. but only if you got the fan to work and it still coming out.

 

same thing happened with my y7.. turned out 2 b the headgasket..far as the fan try the relay cuz eg's are known for fan issues. u can wire it somehow to come on when u turn the key to "on" cant remember how though..

 

I will try replacing the fan relay.

But could it still be bad if it still comes on when I jump it?

 

up for more suggestions and answer.

 

I'll agree with you on replacing the fan relay in the underhood fuse box. But how at all do these symptoms point to the fan motor being bad? OP stated that he hardwired the fan and it ran.

btw. OP. check all grounds. make sure the mounting surfaces are nice and clean. Use a wire brush if need be... faulty grounds can cause some funky problems. Might not be your problem, but its free to try.

 

^ I agree. Come to think of it, isn't there a ground on the thermostat housing? In the course of replacing the thermostat, most people unbolt the little m6x1.0 bolt that holds the ground to the thermostat housing while replacing the thermostat. If that connection isn't clean, no ground. Cleaning is free. I also don't think that the fan not coming on means you have a blown headgasket....that's calling an electrical problem a mechanical problem...different altogether...best of luck....

 

must have been in one of the posts i didnt read, I only read the first post.

 

You are correct sir... no ground for that fan switch I could only imagine it not working properly, if at all.

 

someone may have changed the thermostat too low and the fan switch never comes on. you can buy a lower temp fan switch and replace the sensor on the thermostat sensor..

 

UPDATES? did you figure it out? i have the same problem.

 

It was my headgasket. It was the one thing I was hoping it wasnt.

I replaced it with an OEM one.