claygo

Hello!

I have a 1995 Honda Civic DX 1.5. When I purchased the car, it had a cheap aftermarket cooling fan straight wired into the fuse panel. I bought an OEM style fan and installed it. When I checked to see if it work... it did not. I checked my fuses, and all looked good. I replaced the temperature switch on the thermostat housing... still no fan. I then replaced the thermostat and radiator cap.. no fan. I then replaced the coolant temp sensor underneath the distributor... no fan. I bled the system with car parked uphill and the cap off for 20 minutes... no fan. When I jumper the fan at the temp switch on the thermostat housing... the fan comes on.

Can anyone PLEASE tell me why this fan is still not working automatically as it is supposed to. To my knowledge I've exhausted every possibility.

Riick

Mysterious. Have you checked for shorts in the wire between the cooling fan and the cooling fan relay? Have you tested the cooling fan relay itself?

claygo

The fan wouldn't kick on when jumpered at the switch if the relay were bad would it? And the switch is at the end of the wiring system right? So if there were a wiring issue, it wouldn't kick on when jumpered would it?

gearbox

iTrader: (95)

there are only a few things it could be. the fan itself, the wiring, the relay, the fuse, or the fan temp switch. or possibly air bubbles in the coolant if you did not bleed properly, which can cause the sensor not to work properly.

claygo

So could it potentially be the relay, even though the fan is cutting on when its jumpered at the switch? If its possible, I'll go buy a relay.

I'm really close to just leaving it jumpered, at least it runs that way.

I just can't get it to automatically come on... and I can't figure out why.

claygo

I think I'm just gonna cut the switch connector off, and splice the two wires together. I would leave it jumpered, but I'm afraid the wire will fall out. There is no cure for it. **** it. I'd rather it run too cool than overheat I suppose.

Sucks that I spent over $100 on new parts with no success.

gearbox

iTrader: (95)

no dont give up. the electric fan uses a ton of power and you do not want it running non stop. depending on where you jumper it, the relay could be bad and the fan would still turn on. if you replaced everything else, i would try the relay before giving up.

claygo

I don't really have much of a choice. This is my only way to and from work, and I'd rather it not overheat on me. I switched the relay with the condenser relay... still with no success.

Is there any possible way that air could be getting into the system? Like without there being a coolant leak? Because I let the car sit and idler with the cap off for over an hour. And at the end of the hour, bubbles were still rolling out of the top.

Also, my cooling system appears to never get pressurized, I'm not sure if its possibly because of the cooling fan keeping the system overcooled, but after 30 min of driving, I can pull the cap off. No steam, no pressure, nothing. Think that might have something to do with it?

Riick

My bad. I think you're correct. I just misunderstood what you were doing with the jumper.
Could it be the coolant was pouring in like a waterfall and you were just seeing the bubbles from that? A head gasket issue could cause the engine to push exhaust gases into the coolant, but then you'd have coolant backing up into your reservoir and also you'd find yourself continually adding coolant, and you probably would have mentioned this.
Perhaps you've found the problem! Obviously the fan switch won't get triggered if the coolant isn't hot. Sounds like the coolant isn't flowing through the engine block, doesn't it? Yikes; if that's the case you shouldn't be driving it or you'll mess up the engine.
So what could interfere with coolant flow? Stuck thermostat? Unlikely because you just replaced that. Dead water pump? Unlikely because I think the coolant wouldn't be flowing at all (sounded like you saw a good gurgle in the radiator right?) Clogged coolant passages? Maybe, although I would think it would have to be some pretty spectacular cloggage if the coolant isn't even getting hot!
If coolant isn't passing through the block then this might explain the bubbles too; perhaps the coolant in the engine block is boiling and you're seeing the bubbles produced from that?
Cars can be money pits that's for sure! I've just done the same while trying to figure out what's going on with my car, if that's any consolation.

gearbox

iTrader: (95)

from the last post it sounds like you have a blown headgasket. maybe not severe enough at this point, but it will get worse. constant air in the system is a good indicator and this could be why the fan sensor doesnt work properly. i am betting the ect sensor is having problems too. check the level of your coolant overflow tank when the car is cold. then go drive to fully warm up the car and check the level again. it should be a few inches higher. if it doesnt move, you have no cooling system pressure.

dont worry about the cooling fan doing much. its only purpose is to keep the engine from overheating at idle speed (stopped in traffic). when the car is moving, the flowing air provides better cooling than the fan. also the thermostat should close if the coolant is getting too cold.

claygo

Well, the water pump is definitely working, because its new, along with the timing belt. The head gasket shouldn't be blown, because its new as well. Put on no more than 1,500 miles ago. Is there any way to test and see where air may be getting into the system?

For the meantime, I'll leave it jumpered, it begins to shake a little with no fan running at an idle.

And the coolant DOES get hot, but with the fan running all the time, I guess it keeps it cool enough that it never pressurizes? I don't know.

Riick

You could have a chemical test for a head gasket leak. Inexpensive to have someone do it. It works like this:
http://www.youtube.com/watch?v=QA7KVQq9vKA
Other than that I guess just check all the coolant hoses for cracks and damp spots. Although you said you're not losing any coolant, right?

Sounds reasonable to me. So does it pressurize if the fan is disconnected?

Stock 99

Pressure testing may be your answer.

http://www.cdxetextbook.com/engines/...gpressure.html

http://www.aa1car.com/library/coolant_leaks.htm