Here's my story, I wrecked the car about two months back. (rear ended somebody) I finally put the car back together with mostly new parts, but some junkyard parts here and there. Junk yard radiator and fans. Both work (jumped the plug on the thermostat housing and they both kicked on). The head gasket was done about two weeks before I wrecked. The fans worked then. I have checked all the fuses and the relays I could find. I put a new temp switch on and still nothing. (The one on the thermostat housing) The fans don't even come on when i turn the a/c on. I need help!!!
f22b1

 

Are you sure thermo a is working?

Also, does the ac work? Menaing, if the ac compressor is not coming on....the fans won't come on.

I've been called stupid and slow before so save the typing if that is where you want to go.


So, key on, jump thermo a (t-stat) and both fans come on...yes?

Key off and jump thermo b (upper hose) and one fan comes on..yes?

 

thermos a brand new part, it's working.
I dont think the ac compressor is coming on, your right there.
wouldn't dare insult someone who is only trying to help!! (whichis greatly appreciated)
key on, jumped thermo a and both fans work. correct there
key off, jumped thermo b and one fan works. and correct there.


one thing i have noticed, the temp gauge won't go above half, even with out water in the radiator. I ran it with out water for a couple of minutes to see what would happen, the temp gauge gets to normal operating temp and stays, when i know it's hotter than what is showing. Ran for a minute or two after the temp gauge got to normal temp and still didnt move, reved a little and still nothing. Is this possibly a bad ect sensor?

 

4 or 6 cyl.....I'm going to assume 4.

Well, this could be the fact it is not getting hot enough? Do you have or know someone with an IFR temp reader. The switch/sender for the gauge is a single wire, the ECT is a two wire that "tells" the ECU what the temp is.....#15 in the pic is for the gauge....EDIT #19 is the ECT

A pretty simple test of the gauge (not seneder/switch) is to pull the single wire off. Tuen key on, ground the wire to the head or some thing - DO NOT LET THE GAUGE PEG!!!!!! This will cause damage....so get someone you trust to help.

Is the temp stays around 3:30~4 on the gauge. Sitting at idle in the driveway, it might take 20~30 min before they cycle....you can speed thus up a bit, once the car has a few seconds to warm up (I personally hate rev'ing a cold engine, like the oil to get flowing a bit...just me), hold the rpms around 2 to 2500 for a few minutes while watching the gauge and looking for the fans to cycle.

 

Hello, I'm sorry to bore you with another "cooling fans not working" post, but here's my story... Friday, I pulled into work and noticed a white smoke coming from my 2000 Accord SE, 2.3 Vtec. Obviously, I open the hood and to my surprise I find antifreeze coming out of, possibly, the upper side of my radiator. Anyway, I squeeze the upper and lower radiator hoses and more antifreeze shoots out of the radiator. So, I inevitably replace the radiator. I filled and "amateurishly" bled the radiator. Crank the car up and no leaks, no spews, fans turning, temp running "just below half way", no problems... I didn't drive the car again, after going home Friday, until Saturday night. I made a 20 minute round trip to Walmart and then to Little Caesars. When I come back out of the store, guess what? White smoke, of course. Okay, this obviously was burn off from over spill because there was no leak, but I find out that my fans aren't working AGAIN! The temp was still prefect. I drive 1/4 mile home and park for the night, anticipating an early morning of troubleshooting. After about an hour of pondering and forum/internet research, I began a series of testing and part replacing. I jumped the cooling fan straight to the battery and it worked fine. So, next I take the plug off the switch that screws into the t-stat housing and jump the 2 terminals, both fans run when the key is turned to "on" and the a/c is turned on as well. I replaced the t-stat and switch, "amateurishly" bleed the radiator again after filling it up, crank her up, no fan movement after sitting idle for 30 minutes. For the time being, I have the "plug" jumped so the fans at least cool the engine while I drive. This is where I'm stuck. Testing proves the fan motor still works. It's possible I need a good lesson on bleeding the antifreeze (I've heard that it's very difficult on Honda's). Oh yeah, both radiator hoses get hot so the t-stat opened. Could the "plug" be bad or am I facing an electrical issue? I'm praying that all the head gasket talk on other forums isn't the case because I'm not that advanced yet, lol. Never made it further South than a VCG. Help!

 

Wow that is one long block of text....I'm from west TN so I'm slow.

Ok, when bleeding the air out, be sure the heat is set to max, if you have auto HVAC you might have to start/turn on (?) the car so the HVAC motor will open the heater control valve.


The "no fan movement" after 30 min, did/was the gauge showing over heating? From a cold start and just at idle it could take 30 minutes or more for the fans to cycle. To speed this up you can hold the rpm's up (2~2500) for several minutes.

The fact you jump the thermo switch and both fans run tells you most of the circuit is fine....the switch is the only thing with a ?

 

Okay, so from what I can gather, crank the car, turn the heat up, let it run til it gets to temp with the radiator cap off, bleed the radiator... That sum it up?

I'll try it in the morning! The temp gauge never went above "half way" btw, so that's why I was so clueless in the first place. I'm still a little confused about the thermo switch. I replaced the part that screws into the housing. What is the name of the "plug" that I have jumped right now, and what is the name of the part that screws into the housing? I may need to replace the plug... ?

 

I only said to turn the car on to open the heater control valve if you have auto HVAC....but whatever. Not trying to start a debate we all have different ways of getting to the same place.

 

Im having the same issue ( 96 accord EX V-tec 4cyl)
. tested EVERYTHING fans, relays, and switchs. I bleed the system to the best of my ability.
- turned heater on full, fans off with bleed screw open, and poured away untill steam coming out of the bleed screw was constant ( with car running)
NO FANS
let car fun for about 45min about 6 min after 25 min i revved at 2500rpm for about 5 min.
No fans

im thinking im not bleeding correctly . My temp never went above half way after all of this but i know it works b/c 24hrs earlier my heater hose blew and the gauge shot up.

 

Drive it, keeping an eye on the gauge.

Personally, I refill the system (slowly) with the bleeder open (car not running) until a good stream comes out. Close off bleeder, top off rad and res, replace cap and start car....it seems to work for me.

 

Hey LostAgain,
Regarding your attached diagram, my 96 left fan comes on when the ac compressor is on but the right side will not. Using an IFR, I read between 148-170 on both front and rear hose. I blead air very well also. To test if the temp sensor is bad (is that #12), how do I jump it to test the fan? I didn't understand t-stat. Thanks.

 

yes i just replaced my engine and did not put the ac system back on being the lines where broken and the compressor was seised. would that affect why my cooling fans wont come on?

 

No

 

Hey guys i have a problem with my fans as well I did the paper clip test only one fan comes on and this was on the lower rad hose sensor. Also if I try to see if the same plug has power with a test light grounded on battery I touch the green wire on the harness the fan come on and no light is on the test light. It's the cooling fan that comes on 97 accord lx 4 cylinder. also the ac doesn't work. I have jumped the the ac fan it works. IF you put power to the relay wiring the with the paper clip the cooling fan comes on but if you unplug the ac fan it goes off. I'm confused.

 

Heck, you confused me.

Ok, jump the wire side of thermo A on the t-stat housing, turn the key to "on"/pos II. Which fan comes on - drivers side or pass side?

Not sure which relay you are jumping? If it is the one on the under hood fuse box (pass side fan), try switching the power window relay with the cooling fan realy while the jumper wire is still there and the key on.

If it is the relay between the drivers headlight and the rad (pass side fan), try switching the wires to the "other" relay (ac compressor clutch relay)?

Now I'm assuming the other relays are good.

 

When you put ground to the green wire on the lower rad hose sensor.The pass fan comes on something is making it backfeed. It should be 12 volts right. Also you close the relay for the ac the compresser comes on and ac works but no ac fan.The t -stat is on the upper rad hose right if so the only fan that comes on is the cooling fan after you turn key on then off . I jumped the lower rad hose with key on only the cooling fan comes on (pass fan). And I switched the p/w relay they still work. PLEASE HELP.

 

It sounds like your condenser fan motor is burned out.

Take off the connector and apply battery directly to the fan motor. If it doesn't come on then the fan motor itself is bad.

 

It works i have put power to it.

 

They should both work at the same time except when the key is of, which is when only the passenger fan would work. You must have an open somewhere.

 

It's has wire ground out that is what i think making the ac not work or drivers fan not come on. I'm going to have to take it to a electrical place.

 

What could be open then.

 

Please don't take this the wrong way. I have no idea of what you are doing or testing.

Put everything together in factory set up.

Jump the wire side of thermo a, turn the key to on/pos II. Do both fans run?

No - tell us which one is not running - left/drivers or right/pass side?

Put 12v and ground to the fan that is not running - does it run.

Answer those simple questions without doing "anything creative" and we can start from there.

I want to help but I cannot follow what you are doing or trying to tell us - I'm slow so keep it simple.

 

On switch a only one runs the pass. side and I have put power and ground to the other fan it works. THANKS FOR THE HELP

 

Now I'm starting to follow, again it is me.

You jump thermo A, t-stat housing where the lower hose connects with the key "on" and the pass/right fan runs but the dirvers/left does not.

The relay for that fan is under the "rad support" - between the drivers headlight and the rad, There are two, one for the AC and the other for the fan. You can swap those two just as a check.

 

I have swapped them and both are good