Back Story:

My 1997 Honda Accord LX 2.2L Automatic had 200,000 Miles on it was due for it's BIG tune up. Using tutorials from here I replaced the timing belt and water pump(+hoses & belts).

Unfortunately, something fell into the spark plug cylinder, and I had to pull the head to get it out(if you have young 10 year old nephews who want to help, you'll understand.

I replaced the gaskets, torqued everything correctly, and moved on to replacing the radiator, which had a small leak and needed to be replaced as well.

I hooked everything up, turned it on, looked to be running fine.

The radiator got quite hot, I could steam coming from it, so I shut it down.
I did an engine block test, checked the new oil, sparkplugs, checked the compression of the radiator, all fine, so the headgasket, Valve cover gasket, and radiator are all working just fine.

I turned the AC on and the engine on. Only the Coolant fan ran.
I checked the Radiator fan fuse(all under the hood), it was blown. Replaced. Repeated. Blew again.
I used alligator clips to connect the fan straight to the battery, it ran just fine.
I plugged it into the coolant fan pigtail connector, with the proper fuse, it ran just fine over there.
Back to the Radiator fan side, I replaced the fuse under the hood again. Unplugged the fan, turned on the AC, no problem.
Plugged the fan back in, put a paperclip in to jump the Radiator Fan switch(on the thermostat housing), turned it back on, and it still didn't turn on.

Now based on all the work I did(headgasket, radiator, timing belt, water pump, etc), I've always had this thought in the back of my head, that maybe I forgot to plug something back in, or something got broken in the process, as I believe both fans worked fine before I started.

Any ideas from you guys where I should go next, maybe something I have overlooked, Maybe where I could find the ground so I can double check that?

 

Nicely worded post. We get a lot that require de-ciphering.

To your problem! In my experience the engine should not overheat w/ one fan not operating. Are you sure coolant is circulating? Possible blocked thermostat. I observe coolant when cold through open radiator cap to verify circulation.

Also engine gets quite warm ( 194F) before radiator fans turn on. Was temp past midpoint on the temp gauge in dash panel when you though overheating was beginning. Perhaps you're jumping to overheating when not really overheating?

Have you checked the radiator fan relay? It may have an internal short. You can jumper the power across relay contacts (shop manual essential) to confirm problem is in relay, or check proper relay contacts for shorted condition when removed from fuse box.

good luck

 

Thanks TexasHonda,

I've read the HAF quite a bit since getting my Accord from my dad.
I've seen soooo many posts where people don't give simple info(year, make, model) more or less all the important details. I figure if I'm asking for help, the least I can do is be detailed and try to imagine what questions you guys will ask, and answer those first. I also felt giving a detail of what I had done would give a background on where I might have made a mistake, or where I could have missed something.

The temp. gauge hasn't shown overheating, which also concerns me. It typically goes no high than 1/3rd, a few notches below the half way point.

I've used an Infrared Thermometer to check temperatures and usually the radiator and upper hose get up around 190-200 Degrees F.
It's possible it wasn't overheating, but I know both fans are supposed to come on when the AC is turned on, which doesn't happen.
When I turn the AC on, the condenser fan comes on as it's supposed to, but the Radiator fan blows it's fuse and does nothing.

It may not overheat, but I'd like to keep my car stock and in normal working condition to prevent future repairs, that's the purpose of it being my Daily Driver(My prelude is my fun car. ) By Stock, I mean no non-factory performance mods for this car. Used to be my dad's Daily Driver up until about last year. I'm hoping to get at least another 100K out of it!

I'm actually more worried about it overheating, and not knowing it's overheating. But I figure if I try to solve why the fan isn't working first, I should be able to figure out the temperature issue(if one exists) after that. I was really hoping to find something causing both.

I haven't tested the radiator fan relay yet.
I've done a lot of work on my cars before(brakes, rotors, timing belts, water pumps, etc. but I know virtually nothing when it comes to the electrical aspect or how to test things electrically.

I had to look up how to "jump the Radiator Fan Switch." the other day.

How do I jumper the Radiator fan relay? There's 4 spots on this one. Do I simply jump just the left two, or would I need to jump the left two and right two at the same time?
Thanks in advance!

 

Temps w/ IR gun sound about right for good temp control. My 94EX goes to about 1/3 position and shows 190-195 F temps on engine side hose fitting.

Pull the relay and look for a diagram on the relay showing the relay contact pins and relay solenoid driver pins. You should jump the relay contact pin positions in the fuse box. Wire colors are not much help as these are on the underside of fuse panel.

Which fuse is blowing when radiator fan is connected? Fuse 21 or fuse 34?

good luck

 

I'm not sure which ones are what number, but it's the last row(where there's 3 20 amp fuses), closest to the rear passenger side of the fuse box(under the hood).

On the relay, the coil "slinky" looking side is the relay solenoid, correct?,
So I should be jumping the other side, correct?

Is there a diagram for the fuse numbers?

 

I tried to jumper the Radiator Fan relay switch. When I did, there was a spark, and the paper clip started glowing red, and got quite warm. The fan did infact work, but I don't think it's supposed to have that much electricity running through it.

 

You should download a shop manual. It has the fuse box diagram w/ fuse numbers. See Online Manuals post in diy forum.

Perhaps the wire should get hot. You're pushing 5-10 amps through a small paper clip wire. A VOM w/ 10A capapbility should tell if amperage is too high. Anything over 10 would suggest a problem.

good luck

 

Hey Nova, are you replacing the fuse with the correct size?,and if you jumped it and the fan worked then its a problem in circuitry. I suggest you replace the fuse with the required size and if it keeps blowing place a fuse that is about 5 above the required one. the fuse just helps with resistance in circuitry so you dont damage components. That 12 volt that the battery gives is converted to direct current for the fans.
Hope this helps

 

Yes, I'm using the 20 Amp fuse for the Radiator fan as the online manual shows.

I think I'm losing resistance somewhere, possibly a ground that isn't properly connected. The wiring diagrams show grounds as being numbers like G203 etc, but how the hell do I find them? lol, and test if they are doing the right thing?


All I know is the fan isn't working, fuses blow whenever the fan tries to turn on. I don't know why. If the fuses didn't blow, it would run fine.

I really don't want to load higher fuses on it,(like a 25Amp fuse? or a 30amp,)

I don't think it's supposed to get that hot.

 

When I had a bad fan relay, my temperature gauge started rising while stuck in line getting fast food for a long time. The radiator was relatively new. So overheating is possible.