I have a '93 Accord EX, 150 K kms.
Today I changed the (original) weeping rad, for a new one from a '93 EX-R parts car I picked up. (The parts car had just had a new rad, hoses etc. before a skid of roofing materials fell on it.)

Anyhow. No cooling fans. I let the car run for a long time with no rad cap to 'burp' the system, then put the cap on to build pressure. No leaks, but no fans.

The only way the fans will come on is with the A/C. all plugs and wiring seem OK.

Any suggestions ?

 

The radiator is probably doing a pretty good job of keeping the coolant below the set temperature to turn the fans on.

Is the temperature gauge in the car staying at the normal operating temperature?

 

The temp is in the upper range of normal, not overheating but higher than it used to read.
I had a tip that it could be the fan switch, either loose or worn out. (My parts car has a new one in it)
Only thing, I don't know what it looks like.
Where is the fan switch located, and what does it look like ?

Thanks

 

Here's a picture, but I don't see enough sensors. Maybe someone else knows.

Normally I'd say #14 is the fan switch that's responsible for switching the fans while the engine is running. #15 is responsible for switching the fan after you turn off the engine.

But the parts site calls #14 a "sensor" rather than a switch. AND the drawing doesn't show the sender for the gauge, nor the sensor for the ECU in it's normal place (screwed into the head). So maybe the fan control system is different here?

Unplug #15 & use a paperclip to jumper the wire. Turn on the key - does the fan run? Leave the jumper in & turn off the key - does it run now? I'm hesitant to tell you to do the same test with #14, incase it's the ECU sensor.

Look in the DIY section, there's a sticky post about shop manuals. Get the one for your year & look at the cooling system wiring drawings.

ps. I deleted your other post, it kinda duplicates this.

 

did you bleed the system properly ?? did you loosen up the bleeder screw ??
If not,, engine off, loosen up the bleeder screw make sure that there is no air in system , also make sure that the t-stat is opening up properly lower hose almost as hot as top hose .. if lower hose is warm or cool, t-stat is closed or partially closed ....
If it was not overheating prior to rad replacement i would try to bleed system properly first using the bleeder screw

 

Desert, does 93 have a funny system I'm not aware of? What happened to the ECU temperature sensor? And the sender for the dashboard gauge?

 

Hi all, and thanks for the replies.
I've solved the problem. My parts car had receipts for a recent new rad (which I used), thermostat, fan switch and some other odds and ends. I looked up in a parts house site what a fan switch looks like. I then traced the cooling system looking for something new and found it under the air intake house, in the thermostat housing. I just switched the whole housing with new t-stat and fan switch, and now have cooling fans again.
I think the fan switch was faulty for a while. These cars must be so well engineered that it only got warmer, not 'hot'.

Cheers

 

Usually with a good cooling system, you have to work to get it to overheat. Driving even 5mph pushes plenty of air through the radiator.

Sometimes when you TRY to get the fans to run, you have to block off the radiator with some cardboard or something because there's enough air moving around anyway.