Hey guys,

Need your help here if any of you may know what could be wrong here.

I have a 93 civic hatch, the previous owner had tapped into the wires to the fan because the fan wouldn't kick in when the engine was getting warm.

They didn't cut the wires, just spliced into it so they could power the fan on with a toggle switch in the cabin. I pulled the fuse that they had in the + wire going from the switch to the fan. Still not coming on, I replaced the temperature senser switch that is in the thermostat housing as well but still no luck.

I don't know if it makes sense, but the upper rad hose doesn't get hot, just barely gets warm even after running for a long time. Would a bad thermostat make the fan not kick in? Im stumped, as I don't know to much about engines.

Any help would be appreciated guys, just looking to figure this out before I go nuts.

I haven't replaced the thermostat, I dont know if it was stuck shut would it not alow the hot coolant to touch the temperature sensor in the housing to turn the fan on?

Thanks Guys!

 

Have you jumped the connector for the ECT switch yet? If you do and the fan works either the coolant isn't getting hot enough around the switch or the switch is bad.

 

No I haven't, you mean the temperature sensor connector? I forgot all about doing that.

 

Sorry man, that should have read ECT connector, the one that plugs into the ECT switch in the thermostat housing, if you jump it and the fan works either the switch is bad or the coolant isn't hot enough.

 

Okay, So if I jump it and the fan kicks in.... It means the coolant isn't hot enough... which means what? the thermostat is toast or what?

The upper rad hose doesn't get hot, not even warm. It's not air locked, we have let it run and bled out the air.

 

Either that or coolant isn't circulating (bad waterpump or somethings clogged)

I've been following your other thread on the other forum as well, just trying to keep them both straight.

 

bleed the system correctly, bubbles can cause the fan to not kick on.

 

beat me to it

 

The system has been freed of air, I ran the car with the rad cap off for half an hour or more just letting the air bubbles escape. Before I shut the car off there were no air bubbles bubbling out of the rad.

A Waterpump eh, I suppose thats a bitch of a job to change? Im sorry guys, I dont know a whole lot about engines.

 

Basically the same as timing belt job.

 

Never did one of those before either, haha.

Well now, this seems like a shitty situation lol I was hoping to have the car done for Speed sport haha.

 

You've still got almost a month. Try a thermostat first, see what happens, or at least test the one in the car (put it in boiling water and see if it opens at the correct temperature.

 

I have another thermostat from an eg out in the garage, it's used but worth a shot.
I will jump the connector tomorrow and see what the out come of that is.

Thanks a lot for the constant replys man!

 

ACTUALLY, is it possible for the underdash fuse for the radiator fan to be blown causing it to not come on?

I guess that wouldn't explain why the upper rad hose isn't hot though haha.

 

Go for it

Np, not often I see a semi-local guy on here.

 

Yeah man haha not very many NB'ers on here!

ACTUALLY, is it possible for the underdash fuse for the radiator fan to be blown causing it to not come on?

I guess that wouldn't explain why the upper rad hose isn't hot though haha.

 

Also I read there is a fan relay that could also be bad?

Where is it located?

 

Yes but see below

Underhood fuse box by the battery IIRC.

 

IIRC? What does that stand for?

Ill check the relay tomorrow aswell. Is there a trick to telling if a relay has gone bad?

 

Bleeding the cooling system properly may take 20-30 minutes:

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below (hint: the bleed bolt is located where the upper radiator hose connects to the engine):

 

Thanks Ron, i will give it another go tomorrow!

 

Little update guys, I explained it wrong I was mixed up.

The top rad hose is getting super hot like normal, and the bottom rad hose is cold as ice. It's building up a lot of pressure. Would that sound like a stuck closed thermostat?

Fan switch is working A1

 

Ugh, I have no idea guys....

I installed the new thermostat, before installing i drained the coolant from most of the system to prevent spills. After I installed it, I filled the radiator back up and hoped for the best. and bled the system accordingly.

The fan is still not kicking in... Thermal switch could be bad as I bought it from a buddy.
I put it in a pan of hot water and checked continuity with an older analog ohm meter. Maybe the ohm meter cant read the small amounts? I dont know.

The top radiator hose is nice and warm, not hot like it was before I installed the new thermostat. The bottom radiator hose, well its still cold. Even after taking the car up and down my road multiple times after it warmed up to normal operating temperature.

The bottom hose seems to have lots of pressure in it, just not warm like the upper rad hose is. I dont know what is going on guys, im 100% stumped