Can anyone help with the following problem (91 Civic):
Both the radiator and condensor fan are always on. This is a new problem so it's not because it was wired incorrectly. Normally both fans should run only if the A/C is turned on. I have already done a few hours of troubleshooting including checking both relays, A/C diode, checking for wires shorted to ground and even poped off the lid on the ECU to see if any compoments were fried.
Has anyone experienced this or have a guess what is wrong?


[Modified by er, 7:15 AM 4/21/2002]

 

no clue wierd!!!

 

and WHY are we complaining about this? having two fans would be a godsend if it were in my car.

 

Mine does the same but i gave up on trying to figure out why its happening

 

My car did it, just cause the thermostat kept sticking and the engine was always running hotter than normal...it was weird. Changed the thermostat and gasket, everything has worked fine since

 

Reach behind the block under the intake manifold and unplug the two wire conector that is above the oil filter. It may have a rubber boot on it. That should turn the fans off. If it does replace that switch.

 

Yes. I see the two wire connector exactly where you described. based on the wire color codes my wiring diagram calls it the coolant temperature switch. I've made one quick attempt to remove it but the rubber boot is baked on hard. It does not pull off and I'm concerned about pulling on the wires without first taking off the boot. I'll try to take it off this weekend to see if it shuts off both fans and replacing switch if needed. If this switch controls not only the radiator fan but the condensor fan as well then it's likely it's the culprit.

Thanks

 

I concur, I had the exact same problem with my fan sticking on once (except no AC in my car). The thermoswitch had failed. Honda (smartly) used a kinda reverse-logic switch, better to be always on then never on when it does goes out.

The boot is tricky, even when it isn't cracked its on tight, becareful and use something like a pick or small screwdriver to work it off. Oh yeah, the thermoswitch is like ~22mm (not 100% sure on this), so make sure you have a big enough size socket and it better be a pretty deep one too. It will need to clear the electrical connections, kinda like the way you need a deep socket for a spark plug (you'll see what I mean). Can't remember why I didn't use a wrench, I think it was due to no room or for better leverage.

 

The switch is no good! Both fans shut off when the connections were temporarily pulled off the thermo switch. As you said, it looks tight for a wrench so will probably have to find/buy a deep socket that fits. I'll just wait till I get the new thermo switch in front of me to determine the size wrench needed.

Stumbled onto a torn outer left CV boot. Its a mess. Don't want to spend much on repairs so I'll price out a boot kit and compare with a refurbed complete shaft. The existing rebuilt shaft is only 30k miles. This seems too soon for a boot to tear. I would think there should be at least 40-60K left in the axle and other boots. Maybe the huge jackrabbit (looked to me the size of a small coyotee) did it when he ran into my left front side 2 months ago. Everyone in the car screamed making it an event I won't soon forget.

I was wondering if it's time to replace the little 1.5 liter sedan's timing belt since all the auxilliary belts are already over due for replacement and the alternator is real noisy. I hope it's noisy because of the belt and not because it's worn out from the extra demand running both electric fans for about a month or two.

I changed the existing timing belt and water pump 45K miles/5 years ago. Since an aftermarket belt is under $20 and removing the auxilliary belts is needed why not go all the way to the T-belt. If the T-belt should be replaced at 60K it's probably worth doing now, but if it can go to 90K with little risk of breaking i'd rather hold off (or sell off) before 90K is up.

Thanks to Lancaster for troubleshooting and to the Bay Area for helpful advise; you saved me lots of time!

 

Large jackrabbit.... ouch! I had a dumb cat jump out in front of me once. Luckily I got him right with the middle of the car, he left fur in the airdam and some back in the exhaust b-pipe. But no real damage, at least to my car. I felt bad and flipped around thinking I'd take him to a vet or push his carcass into a bush, but he was gone.

Oh yeah, you probably realize it but just in case... that thermoswitch is in the coolant passages. So don't run the car right before this and get ready for it to pour out and swap the new t-switch in quick. Didn't want anybody burning themselves or making a mess.