1992 Accord, fans won't respond to jumping the thermo switch while it is on and/or running. But the passenger side fan will engage when jumped after the car turns off (meaning the paperclip is already in the wiring before turning off the car). Switched relays, used the test light and got one terminal to light with the car off. Two lit up with the car on, and a third one weakly lit up but it simultaneously made the drivers side fan engage. That is why I am posting, this is the weirdest result I've seen yet, I don't know where to look to fix this. There is a lot of grease on the wires under the relay box, don't know if that matters.

I am getting full volts all over the system, as proven by the fact that fans come on. I took out the fan timer switch and the circuit board was still squeaky clean. Not sure how to test the timer so I put it back in. If I can get it to reliably jump from the wiring connector going into the thermos switch then I can diagnose the thermo and move on to cleaning the headliner. Any suggestions are more than welcome.

Oh nothing happens when I turn the a/c on either.

 

The dielectric grease at the bottom of the fuse box assembly is normal. The fan timer will likely be your issue even if it isn't burned. I would get another from either the dealer(what I would do) or from the junkyard( what I wouldn't immediately do, but I can understand if you did). It's not often these go bad but they do.

ps make sure you are jumping the correct fan switch.
http://www.hondapartscheap.com/auto-...ater-pump-scat

It should be part 14

 

Thank you for the response holmesnmanny! I heard the fan timer switches get wacky on these models, so I am not surprised with your conclusion, makes sense. What about the fact that if I ground one of the relay terminals the drivers fan comes on? Doesn't that seem weird? I know a couple of guys with similar cars, maybe they'll let me switch the fan timer just to test it, hopefully that fixes it. All the components obviously work, just not when asked to do so, I still don't know why I can't jump it with the car on, but I guess I should eliminate this fan timer switch as a variable before I continue digging. Would it hurt to clean the 20 year old dialectic grease on the wires and reapply?

 

I tried cleaning the grease before lol and it wasn't working so I just added more grease and let it be.

I'm not going to say that the fan timer is the issue but it's likely it is. It could simply be a wire broke somewhere within the wiring or the pin is pulled out of a connector somewhere.

rockauto has a bishko shop manual on cd rom that would have detailed electrical diagram on cd for you to trace the wiring for only $25. I used to have a shop manual but I'm not sure what I did with it.

What you may need to do is to get a "tone sender" off amazon that you put on a pin and it will send "tone" through the wire. Then you will use a "receiver" to listen along the line and wherever it stops is where the break is, provided the wiring has a break in it.

 

Just me but it sounds like you are jumping the wrong switch?

The switch on the upper hose only controls the one fan when the key is off.

The switch on the lower hose controls BOTH fans when the key is on.

 

Thank you for that, I was actually jumping the wrong switch. I'm still not out of the woods though. I followed the flowchart from the Honda manual to start getting a little more scientific about it:





1. Check fuses nos. 2, 8 & 39: Working
2. Disconnect relay and put jumper between terminal 2 and 4: Fan works
3. Voltmeter between terminal 1 and 3, turn on a/c and fan switch, turn car to RUN position: Nothing happens
4. Check terminal 1 for battery voltage. Condenser fan comes on?!!

Steps 3 and 4 is where stuff gets weird.

On step 3, my a/c is not fully operational right now, so I don't even know if step 3 can be tested without the a/c?

On step 4, I am checking the terminal for voltage by using a test light. When I do this, the driver's side fan comes on and there is a dim light on the test light. This is the strangest part to me, unless this is what is supposed to happen?

Not really sure what to make of that, apparently whatever the outcome is you are supposed to repair an opening in either the yel/blk wire if there is voltage, or the blu wire if there is not voltage. No mention of the fan timer, though I still agree with you that I need to go grab one and throw it in there. Just wanted to update you on my textbook testing to see if it sounds familiar.

 

Still messing with this car, no success yet. Just as an update, I have 12.28v going to the ECT sensor (thermo switch on the upper hose) and 5.03v going to the TW sensor (near the thermostat). Should I be concerned about the 5.03v?