Mychal71

1999 Honda Accord LX, 4 cyl. auto.

The car has been heating up when idleing for a bit every now and then. Thought it was weird, but now it is becoming more often, but as soon as you start driving again, it cools back down.

Now when the a/c wont work unless you are going 75mph down the freeway. And then it blows warm air once you slow down into town.

I checked the fans today and neither one of them come on. I felt the radiator hoses and they are pressurized.

I checked the fuses and switched out the relays and it made no difference. Could it be the thermostat or some sensor that would cause the fans not to come on at all? or maybe a sensor somewhere?

I doubt both fans would go bad at the same time.

thanks in advance.

TheMuffinMan

iTrader: (1)

Power the fans straight from the battery.

Fan Switch, etc

Mychal71

how would I go about doing that?

thanks!!!!!!

maddoggpt

you would measure the length between the fan switch located on the drivers side underneath the radiator(i think,I'm not near my car right now) and then run a positive and negative wire to the switch(basically making a jumper). Correct me if I'm wrong but thats what i did in a similar situation and it worked for me.

TheMuffinMan

iTrader: (1)

Just put a wire straight from the fan's power plugs to the battery terminals and if they turn on the fans are good.

Mychal71

when I put a wire straight from the battery to the fans power plug, do I need to run one wire to the positive side of the battery and one to the negative?

Do both fans run off of the same switch? I find it weird that BOTH fans are not coming on. They run independently depending on if the a/c is turned on...correct?

TheMuffinMan

iTrader: (1)

Haha yeah, that's how power works

I can't recall which is positive/negative if there's a black one, go with that being negative. I think it's blue/black.

And you can use any wire, I just had stereo wire laying around and used that

Mychal71

Okay checked the fans....you were right, one blue one black wire. Both fans are working when hooked straight to the battery. So the fans are good

I havent checked the switch you mentioned. Where exactly is the switch at I need to check?

I'll check that switch tomorrow. Can you tell me how I check that switch again? I'm not sure I understand how to check the switch.

thanks again.

EDIT: I just jumpered the switch/sensor that comes out of the thermostat housing (what is this sensor called?) I unplugged it and jumpered the two pins on the plug itself and BOTH fans turned on. I tried it with the a/c on and the a/c off and BOTH fans turned on either way.

What does this mean? What next? Other switches?




Modified by Mychal71 at 9:41 PM 6/17/2008

TheMuffinMan

iTrader: (1)

Hmm odd.

I would assume at that point, since the fan switch and both fans are working (glad that worked for you btw)

And with the A/C it's possible that the car was cooling itself off on it's own turning on automatically, though with AC on they both should be going.

My guess would be what's called the fan control module.

It's a box behind the glove box area that you'll want to try to swap out.

Also just in case, bleed your coolant system as well to ensure there's no bubbles or anything in it as a bubble in the wrong spot can cause problems.

Mychal71

when I bypassee that sensor on the thermostat housing, both fans came on with the a/c on and with the a/c off.

how do I bleed the coolant system?

Is there a way to test that box behind the glove box or do I just need to get a new one and try it out?

TheMuffinMan

iTrader: (1)

Bleeding it I'd just get a shop to flush the whole system. If you want to bleed it then do a search and there's a step by step doesn't have to be accord specific I think I used one in the prelude or integra section.

And to test it I can't give you much more info, I just know several others have had that be the culprit.

Mychal71

Question about the fans. Should they both ALWAYS turn on together or does one come one when the engine temp gets up and the other come on only when the a/c is on....or?

I was searching around a little more and some mentioned a continuity test on the sensors. How would I do this exactly? I have a multimeter.

Also the fan control module....is that a dealer item or is that something autozone, etc. would have?

Thanks for all the help!!!!!!

TheMuffinMan

iTrader: (1)

I'd hit up junkyards first.

They'll both come on if AC is on, I believe just the passenger one will come on sometimes for cooling the motor

Mychal71

I talked to my girlfriend (her car) Not sure if this info will help narrow it down or not.

The heating up thing started before the a/c quit. While she was idleing for more than a few minutes, etc the temp gauge would slowly start climbing until she started moving or turned on the heater on full blast. This was happening for a while.

Just recently the a/c stopped working at idle and low speeds. you have to get on the freeway in order for cold air to blow, otherwise hot air.

I had thought all of this had happened at once, but it was first the heating up, then later on no cold a/c.

let me know if this makes a difference. possibly two different sensors since it happened at two different times?

I looked under the dash for that fan control module. I see two boxes if I look up under the passenger side dash where the heater box, etc. is. How do I know which on is the fan control module, or is it actually behind the glovebox as in, I need to remove the glove box.

also, is the "fan control module" the correct name for this part?

thanks again.


Modified by Mychal71 at 7:33 PM 6/19/2008

Mychal71

Okay I actually replaced the sensor/switch in the thermostat housing and now my fans come one once the temp starts to rise.

BUT, they BOTH come on at the same time. Once the engine temp drops, they shut off again. Should both fans be coming on because of engine temp? I thought one came on for engine temp and one was for when the a/c is on?

The a/c still blows warm air and turning the a/c on does not make either one of the fans come on at all. The engine temp is the only thing that effects the fans.

Any suggestions?
and still waiting for a reply on my last post about the fan control module

Bulli Kid

my a.c fan us junka but before when i turn
A.c on my passanger fan turned on , now it doesnt.
also the fan used to come on after the car was off randomly, now it will turn on right after i start the car, with a stone cold engine. IMo honda fukced up with these cooling systems in out accords.

Mychal71

Okay, I was messing with the car again this morning trying to see why the a/c doesnt work. The compressor/cluth doesnt come on/engage or anything. So I bypassed the a/c pressure cut out switch that is on the drier in front of the radiator/condensor. Turned the car on and the a/c clicked on, the fans kicked on and it blew nice cold air.
So I am guessing this would mean that that switch is bad.
My question now, is that if I remove that switch will all of my freon leak out? Will I have to get my system recharged?

Thanks!!!

Bulli Kid

yes freon will sneeak out.

Bulli Kid

i went to my car and turned it an as well as A/C and jumped the A.C switch and only the passenger fan turned on. Not the A/C fan.

Bulli Kid

my clutch only kicks in when i jump it to the battery. any ideas