New to forum & really need help-I'm without a car until I fix this! Older threads I've looked at don't help me. Don't know what to do next.
This is my first major attempt at DYI due to financial constraints. I probably know just enough to get myself in trouble. My Radiator had a crack at the top so I replaced it with one from parts store. Decided to also replace the thermostat (Honda part). After replacing both, the fan still didn't come on (ran engine 15-20 min). Both top and bottom radiator hoses were hot to the touch but engine didn't feel hot. Installed the thermostat in same position as the old one, with arrow pointing up (did not test it before I installed it).
So I tested the fuses (under the hood only) and then bypassed the fan switch-and the fan worked. Did not test the fan motor since didn't have the proper tools & also figured the bypass test answered this. So bought a Honda fan switch. Re-drained the radiator, installed it, refilled the radiator (using Honda blue) - and the fan still doesn't come on. It runs when I bypass the new switch (I checked this again), and when I run the AC - but won't turn on when the engine temp warms up. Temp gauge holds at around 1/3, raising slightly when I let the engine idle 20 minutes. What next? What have I missed?

 

Seeing how the temp gauge is working just monitor that and try this. At idle the car may not need the fan to come on, so run the car at 2,000 rpm for about 5 min, keep close eye on temp gauge. See if fan comes on anytime during those 5 min. Keep interior fan off during this test.

 

Thanks for the input. Tried this and the temp gauge stayed right around a third of the way up (didn't even hit the halfway mark) and the fan didn't come on. Radiator, hoses & lower engine hot, but upper engine remained cool. Also, got a lot of exhaust from the tailpipe. Pretty cold outside today so hoping it wasn't anything problematic. Could the new fan switch be bad? Is there a way to check for this besides the bypass test?

 

Are you sure you plugged in the connection to the fans? Or the wires may be damaged when you removed the radiator?

 

I was very careful, but anything is possible. There was a lot of antifreeze spewed over the radiator due to the leak, and even though I cleaned it up, maybe it caused some damage?
Regarding the fan connections - Yes, I have disconnected and replugged them again. I'm going to go out and check the one on the lower passenger side. I never actually unplugged this one - just slid it off the fan frame.
This might be a stupid question, but just wondering if the fan switch bypass test actually confirms that the fans are okay? Could there be another reason the fan is not turning on when the engine reaches operating temperature - even though both fans turned on when I did the fan switch bypass test?
Remember that I did NOT test the fan motor since didn't have the tools. Thanks!

 

Just checked the fan connections and all 3 are solid. Ran at idle for 10 minutes. Gauge up to same 1/3 point. This time though, the radiator and upper hose were hot, but the lower hose was only hot right near the thermostat housing - not farther down the tube. The clamp at the housing has also slipped a bit. No leakage, but am wondering if this might affect things? Hose Pressurization? I'm going to wait for engine to cool before I reset the clamp.

 

From the last description it sounds like you have air in the system. And if you have a air pocket at the sensor that will wack it out.
Try this once it cools-
1. remove radiator cap
2. remove the upper radiator hose from the radiator
3. hold that hose up and fill it with coolant until it starts to come out of radiator, keep holding up hose
4. pinch hose at location that normally connects to radiator
5. quickly slip hose back onto upper radiator and clamp
6. fill again via the radiator cap, leave cap off!
7. start car and let it idle, a little may start to spill out of radiator-that's ok
8. at a certain point the thermostat will open and it will circulate, at that point top off and recap.
9. Run at 2,000 rpm for 5 min and check for fan

 

With the weather getting colder, you might have enough air moving through to keep it from getting hotter. The fan isn't supposed to run until it gets a bit hotter. Sometimes I've had to block the air to the radiator in order to get the fan to run when it's cold out. Just drape an old blanket or something over the grille (make sure it doesn't get into the fan.

 

When you turn on the A/C, do both fans turn on? If only on turns on, is it the drivers side or passenger side fan?

 

Both fans turn on with the AC. The drivers side fan turns on when I bypass the fan switch.