engine cooling fan

[ryan427]

Nothing earth shattering here... the main fan (driver side) quit working today. No surprise... previous owner rigged it to be on at all times (wired straight to the fuse box). I'm guessing he didn't take the time to test the switch (bottom of the radiator) etc. So, I knew this was something I wanted to remedy anyway. Something cool that I realized though... when that fan stopped working, the charging system "came alive" meaning that fan motor was putting quite a load on the alternator. Makes sense that an electric motor on its way to imminent failure would put more load on the electrical system than normal. I am hoping a new fan motor won't tax it so heavily.

Anyway... my question is, any of you ever just replace the fan motor? If so, any recommendations? Is it a real pain? I overthink these things sometimes so I wanted to get some practical advice. I can always pull one from the junkyard. There's an 89LX with 80k miles in a yard close by. The fan on the passenger side doesn't come on when I turn on the AC but it moves like it wants to. Probably a bad motor too. :help:

[ryan427]

Reading the manual again made me realize that the fan running all of the time is actually the AC fan (supposed to come on when you switch on the AC). So, the AC fan was running all of the time while the main fan never came on. I guess the previous owner thought to rig the aux fan to stay on constantly instead of just fixing the main fan that comes on intermittently (passenger side of radiator). Seems the main fan hasn't worked in quite a while. Further testing this weekend...

[Oldblueaccord]

Reading the manual again made me realize that the fan running all of the time is actually the AC fan (supposed to come on when you switch on the AC). So, the AC fan was running all of the time while the main fan never came on. I guess the previous owner thought to rig the aux fan to stay on constantly instead of just fixing the main fan that comes on intermittently (passenger side of radiator). Seems the main fan hasn't worked in quite a while. Further testing this weekend...


Not to throw you off but my main fan never comes on in normal driving/idling. The car just never gets hot enough. Only at maybe 3000' feet or more of altitude do they come on or when the AC button is engaged with the fan switch on.

Every car is different but that how mine operates. Since where close in area its prolly pretty cold to get the car warmed up. Id still check the fans out.

I never have messed with the fan motor themselves. My ac fan squells a lot so I blew it out with compressed air about a year ago and thats it. I got a second set complete JIC it goes out completely.

[lostforawhile]

if your main fan never comes on, your engine is never reaching normal operating temperature, possibly a stuck open or missing thermostat, or the temp switch in the radiator is bad, the engine reaching normal temperature and the fan cycling is part of several normal service procedures. If you have an LXI the controls for the fans are a lot more complex then the dx or lx

[lostforawhile]

EDIT I didn't notice who posted lol, you probably already knew this sorry :uh:

[ryan427]

Good info. The motor in the main fan is definitely cooked. Probably from being wired to run constantly for so long. When I try to push the fan blades backwards, the motor "catches" and starts to turn. Makes an awful sound. I can't test the switch until I "de-rig" it and put the wiring back how it is supposed to be. Local Napa has a fan motor. Shouldn't be too hard to replace. Famous last words. The AC fan is definitely cooked but I can wait until March when we start getting in to the 80's again then. It looks like a different motor so I might have to grab an entire AC fan assembly... Junk yard for that one.


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[lostforawhile]

on the LXI the control for the fans can also run the AC fan with the time delay, if the temp is over a certain set point, it also has two different temp sensors, I know they are moving the wiki stuff somewhere else so the manual is down at the moment. are you planning on running AC? I was going to suggest if you aren't, you can set up a heavy duty relay with the radiator switch to make the fans automatic again, if you can't figure out the factory system, and bypass the time delay etc. I'll see if I can figure out how to get the wiring diagram off of my PDF of the electrical manual.

[Dr_Snooz]

I don't think it will be too hard to swap out a fan motor. Even if you have to make some changes to the mounting bracket, it should be relatively straightforward. While you have it apart, inspect the fan blades carefully to make sure they are in good shape. I've had the blades strip out on the motor. Motor spins, but the blades don't move.

[lostforawhile]

for some reason, the 89 electrical troubleshooting manual, shows the diagrams for the fan controls for the lxi, but the description of how the system works, is for the carb models.
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[ryan427]

Thank you guys for taking the time to help. Went ahead and yanked both fans out. Straight forward as it gets... Pull some fluid out of the radiator, Disconnect the top radiator hose, unclamp the other hose (my fingers are touching both) and move it out of the way. Main fan (passenger side) is held down with 4 bolts while the AC condenser fan is held down with 3. Unplug connectors (prior to unbolting) and out they come. You can see the wiring job the previous owner rigged up. Not exactly factory but hey, it worked. And he put an inline fuse for added safety! [emoji6] Pics below.

The main fan housing. Isn't in the best shape so hoping the one in the junkyard is better. If not I'll buy a new one. Found one here: 1989 Honda Accord Radiator Cooling Fan Assembly - AM Autoparts (http://www.am-autoparts.com/1989/Honda/Accord/RadiatorFanAssemblies/AM-63063416/193246.html) .

Will definitely test that thermosensor too... http://tapatalk.imageshack.com/v2/15/01/25/97f34ebf7d771794cde9f7c3e03217d8.jpghttp://tapatalk.imageshack.com/v2/15/01/25/4b203aa2696a40a0a859d40944321170.jpghttp://tapatalk.imageshack.com/v2/15/01/25/8a5ef9dc72d70bcb24c39d21e330e1e4.jpg


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[ryan427]

Dropped the new fans in today... New, used ones. $60 for both from an 89 LX with 101k miles on it. I tested them and they work beautifully. When I switch on the AC, both fans power on as designed. The only thing is, I couldn't get the main fan to click on (by itself and without AC on) even idling at 2500 RPM's for a few minutes after driving 10 miles. But the temp gauge inside never went above a little less than half way. Weird. Either oldblueaccord is spot on, my temp gauge is wrong (doubtful), or the thermosensor is in fact, bad. No signs of overheating but I'll keep close watch on it for now. Made sure to clean the blades and used a little compressed air. Seems to be good to go for now. I want to say thank you again to OldBlue, Lost, and Snooz. You guys didn't try to make me feel like an idiot, even with such a basic issue. I really feel like I am part of a community here... makes me feel better about driving a 26 year old car with 270k miles, 80 miles a day. Still getting 29.8 mpg thanks in large part to this forum. My first Accord of this generation, relatively "green" mechanic, and a bit of a learning disability (I think). That's saying something about these cars (some of the best ever) and this awesome forum. Dry your tears and drink your beers!:beer:

[lostforawhile]

dude you are in Thomasville? HOLY SHIT!! another member thats not 500 miles from me, I'm in Moultrie

[ryan427]

Nice! 26 miles away. We need to cross paths at some point. Thanks again for the wisdom!


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[lostforawhile]

Nice! 26 miles away. We need to cross paths at some point. Thanks again for the wisdom!


Sent from my iPhone using Tapatalkall the years I've been on here there has never been another member closer then 2 hours to me, I'm in the middle of nowhere, as far as your sensor, unplug it, and jumper the terminals in the plug, turn on your key and see if the fan comes on, if it doesn't see if the relay in the underhood fuse box is operating, I just realized you have an LX not an LXI so the system is much simpler. The fan controls on the LXI are ridiculously over complex

[lostforawhile]

check fuse 15 in your dash fuse box, check fuse 9 in your underhood fuse box, the system on carb cars is really simple, when the key is on, power is supplied to one side of the fan relay by fuse 15, when the thermoswitch in the radiator reaches it's set temp, then it provides a ground to the relay, which provides power to the fans, through fuse 9, on the dx and the lx, both fans are simply wired together, and there is no sub fan relay in the underhood fuse box. The AC turns on the fans by providing an additional ground to the thermosensor, there should be a blue/black heavy wire coming out from the fuse box, this is supposed to go to your fan motors, there should be eithier a blue/black smaller gauge wire or a blue wire going into the fuse box, it's the seven pin connector on the bottom of the fuse box, and should contain both wires. The diagram is confusing on the switch wire color, as it shows both the LXI and DX wiring on one diagram. the blue wire from the AC circuit, is connected through a junction connector under the fender behind the right headlight.

[Oldblueaccord]

Dropped the new fans in today... New, used ones. $60 for both from an 89 LX with 101k miles on it. I tested them and they work beautifully. When I switch on the AC, both fans power on as designed. The only thing is, I couldn't get the main fan to click on (by itself and without AC on) even idling at 2500 RPM's for a few minutes after driving 10 miles. But the temp gauge inside never went above a little less than half way. Weird. Either oldblueaccord is spot on, my temp gauge is wrong (doubtful), or the thermosensor is in fact, bad. No signs of overheating but I'll keep close watch on it for now. Made sure to clean the blades and used a little compressed air. Seems to be good to go for now. I want to say thank you again to OldBlue, Lost, and Snooz. You guys didn't try to make me feel like an idiot, even with such a basic issue. I really feel like I am part of a community here... makes me feel better about driving a 26 year old car with 270k miles, 80 miles a day. Still getting 29.8 mpg thanks in large part to this forum. My first Accord of this generation, relatively "green" mechanic, and a bit of a learning disability (I think). That's saying something about these cars (some of the best ever) and this awesome forum. Dry your tears and drink your beers!:beer:


Happy to help!

Come up and ride route 129 the Dragon this spring we will get those fans to come on!

[ryan427]

Sweet. I'll check all of that plus jump the thermosensor harness. I really feel like the fan should have kicked on after driving 10 miles and revving at 2500+ rpm's for a few minutes. It was about 55 degrees outside when I was messing with it so maybe that has something to do with it. I can tell the thermostat has been replaced (evidence of orange sealant) so maybe the previous owner installed a lower temp t-stat. Will inspect all of the electrical and go from there. Ordered a carb today too so I feel like I'm making progress. [emoji120]


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[ryan427]

Happy to help!

Come up and ride route 129 the Dragon this spring we will get those fans to come on!

Hmmm... Maybe after the new carb!


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[lostforawhile]

where did you order the carb from? importcarbs.com has the best prices, plus he's been in business forever

[Oldblueaccord]

EDIT I didn't notice who posted lol, you probably already knew this sorry :uh:

Lost every new year I take you off block and start over so np with your comment. only thing i can think of is the car never hits the 226 mark to get the fans to come on. I run a t stat that's fairly new but I only have the stock temp gauge to go buy but I think its run normal temps its whole life.

[lostforawhile]

Lost every new year I take you off block and start over so np with your comment. only thing i can think of is the car never hits the 226 mark to get the fans to come on. I run a t stat that's fairly new but I only have the stock temp gauge to go buy but I think its run normal temps its whole life.

the reason I ask is the manual mentions allowing the car to come to normal operating temp by allowing the fan to cycle twice, so even at idle it's normal for the fans to cycle, as old as these cars are, I wouldn't be surprised if the fan switch may have gone out of calibration etc, just a fact of life with old cars

[ryan427]

where did you order the carb from? importcarbs.com has the best prices, plus he's been in business forever

That's who I went with... National was a little less expensive but I would have had to pay to return the core. Was a wash. I also went with Importcarbs because of recommendations here. Crossing fingers I can remove and replace without total destruction.

[ryan427]

Now I just need to figure out if I have a Denso or TEC thermosensor for fan I/O. Looks like Denso is no longer available. Honda factory part (TEC) is $35.00. Might have to go to NAPA for this one...

[lostforawhile]

Now I just need to figure out if I have a Denso or TEC thermosensor for fan I/O. Looks like Denso is no longer available. Honda factory part (TEC) is $35.00. Might have to go to NAPA for this one...

I would bet there are a number of Honda thermos sensors that are threaded the same and switch on at about the same temp,

[ryan427]

Probably. I overthink these things. I need to just pick one up and get my ass out there and change it out.


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[lostforawhile]

most Honda stuff runs the fans about the same temp, so if you have to, get to the yard and start looking at late model stuff for newer available sensors, that fit, make a list of that will fit, then do some research on the operating characteristics of those sensors, chances are a late model available sensor will work

[Dr_Snooz]

for some reason, the 89 electrical troubleshooting manual, shows the diagrams for the fan controls for the lxi, but the description of how the system works, is for the carb models.

If it helps, there is a wire diagram, followed by troubleshooting flow charts starting on p. 23-4 of the '89 USDM Service Manual. I only mention it because it took me FOREVER to find that info. It's not in the Cooling section, not in the electrical section. It's in the A/C section. Very intuitive.

[lostforawhile]

my scanner is fixed, so I can scan any of the fan wiring diagrams you need

[ryan427]

Thank you both. I haven't driven the car in a week because of the carb. Gonna get out there tomorrow and change out the carburetor/test the fans. Wish me luck. This carb thing has me nervous but most are telling me it's really not difficult. Again, overthinking.


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[ryan427]

Jumped the little harness and... Nothing. I swapped the fan relay and checked the fuse in the engine compartment fuse box... Nothing. Checked the fuse under the dash... Still nothing. All fuses and the relay are good. Both fans fire up when the AC is switched on. But the main fan won't come on by itself. Hm. All the wiring looks fine but there's gotta be a problem somewhere along the line.


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[lostforawhile]

Jumped the little harness and... Nothing. I swapped the fan relay and checked the fuse in the engine compartment fuse box... Nothing. Checked the fuse under the dash... Still nothing. All fuses and the relay are good. Both fans fire up when the AC is switched on. But the main fan won't come on by itself. Hm. All the wiring looks fine but there's gotta be a problem somewhere along the line.


Sent from my iPad using TapatalkI was just down at pick and pull, I completly forgot to grab you a thermo switch, but sounds like thats not it anyway, the AC relay simply grounds the wire from the radiator switch, there is a junction connector under the fender, the thermo switch has two connections, one is a ground, and the other grounds the relay coil, since the fans come on with the AC, then the relay, and fuses are all good, either your thermo switch is bad, the ground connection is bad, or the connection at the junction connector is bad. you should be able to ground one of the terminals at the thermo switch, and the fans should run. if it doesn't, the issue is in that wire or the junction connector where it connects to the wire from the ac, if it's the wire, you simply have to run another wire from the junction under the fender to the switch plug, and make sure the other wire has a good ground

[ryan427]

Hm. I think I got all of that. I pulled the battery out today to get a better look at the wires. There's so much wire wrap around them it's difficult to tell anything. Incidentally, the fog lights (factory) don't work either. New bulbs, good fuses, etc. I think the fog light wires run near all of this stuff too. Wondering if a previous battery leaked acid and melted some wires that I can't see. Determined to find the problem as I don't want to re-rig these things again.


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[lostforawhile]

Hm. I think I got all of that. I pulled the battery out today to get a better look at the wires. There's so much wire wrap around them it's difficult to tell anything. Incidentally, the fog lights (factory) don't work either. New bulbs, good fuses, etc. I think the fog light wires run near all of this stuff too. Wondering if a previous battery leaked acid and melted some wires that I can't see. Determined to find the problem as I don't want to re-rig these things again.


Sent from my iPhone using Tapatalkall you would need to do, is find the junction under the fender, tie into the blue wire from the ac, and run a new wire to the thermoswitch, the other thermoswitch wire is a ground, there is a large ground connection under the fender where a lot of grounds are tied together, the ground might be loose there too, you don't need to unwrap a lot of wires, unplug the thermo sensor, and one wire in the plug should be grounded, the other when grounded should make hhe fans run when the key switch is on

[ryan427]

Still haven't figured this out. Fans run with AC on. Jump thermoswitch connector, no fans. When you say "under the fender", do you mean I have to take the fender off to access the wiring?


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[ryan427]

I finally figured this out. Step 1: remove head from ass. Step 2: Read the instructions that Lost wrote. Step 3: use test light to test for power at relay. Light came on but just barely. So I began the process of running a new wire. As I started pulling the wire cover away near the connector that plugs in to the radiator switch (thermosensor), I pulled the wire out only to reveal the break. It was about 7" from the connector. Butt connector with heat shrink, plugged it back in, warmed engine up and fans kicked on. Again, thanking Lost and everyone else for the wisdom.


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