Alright 99 accord with 161k. I just put a new radiator in the other day and noticed my temp fluctuates while driving. At idle it will drop to a few lines about the C mark when slowing down and at idle. It never gets above half way though. The heat in the car is very hot but once the temp starts dropping the heat goes away. Could this be a thermostat? And for the fans I tried getting the ac fan to kick on by turning the ac on but the fan never came on, and the other fan will not come one either. If anyone has any ideas what the problems could be or if there related any input would be appreciated. New to owning an accord. Thanks in advanced.

 

A new t-stat can't hurt and doesn't cost much. suggest an OE stat.

Next be sure to get all of the air out of the cooling system. There are different methods for the 4 and 6 cyl engines.

Does the ac system work? If the ac system is not working, pressing the button will not make the FANS (both) come on. You can start by putting 12v to both fans and be sure that the fan motors are good. If they work we can provide more help.......but it would help to know the engine size (4 or 6 cyl).

 

Oops forgot to put that.. Its a 4cyl. When I did the radiator I got all the air out as far as a I know. Maybe a different method would work. I am actually running out soon to get some alligator clamp wires to test the fans and will let you know what the results are.

 

On the four cyl there is a bleeder valve on the t-stat that is used to get the air out.

 

Ok, How do you go about bleeding it through the bleeder.(new to having a accord)lol. My jeep doesnt have a bleeder so never done one like that before.

 

Here is the procedure, we'll see how the pic comes out.

I'll add a few notes.

1. Set the heat to max and turn the key to "on" - many of the 6th gens have a motor that moves the cable to the heater core. You do this so you can get the air out of the heater core as you are doing this.

2. When adding coolant - bleeder open - as you get close to "full", pour very SLOWLY. You want a good stream of coolant coming out, not a mix of air and coolant.

3. Before starting the car, put the rad cap back on but ONLY TO THE FIRST CLICK, not all the way just the first click. This helps to hold back a bit of the coolant as it expands as it is heating up.

Since you are not sure if the cooling fans are working, you might have to modify the procedure. When you start the car keep an eye on the temp gauge and shut the engine off if it ever gets over half way. You'll want to let the engine run for at least 15 minutes or until the fans cycle before shutting it off.

 

Ok sounds great thanks for the help. I will get back to about the fan motors in a little while..

 

Ok I tested both of the fan motors and they both worked.

 

Have you bleed the cooling system yet?

You never confirmed the AC works?

After you clear the cooling system of air.....there should be a green connector on the t-stat housing - where the lower hose connects. Remove the connector and use a piece of wire or something to jump the wire side of the connector, turn the key to "on"/pos II and see if the fans (note "fans" = both) come on.

 

Yup bleed the system, and yes the ac system does work. I will do that tomorrow when theres some day light and let ya know how it goes.

 

Ok I tried jumping the fans with a paper clip and they did not kick on. I may have done it wrong but I dont think so.

 

Was the "key on". Check the #4 (7.5 amp) fuse in the drivers under dash fuse box.

 

Yes key was on. I will check the fuse next.

 

Here is the circuit diagram from the fans....I forgot about the fuses under the hood but I'm fining it strange that both are out.....again for both under hood fuses and both relays to go out is odd.....so I was trying to think of "one thing" that would make both fans not to work.

 

Okay great I really appreciate it. Didn't get to look at the fuses today, was pouring all day unfortunately. I'll take a look tomorrow and get back to you on what I find.

 

Checked fuse on dash and was fine.

 

You jumped the wires that go to the green connector on the t-stat housing with the key on.....no fans.

You put 12v to the fans and they work.

Check the under hood fuses for the fans....listed in the diagram I posted. Next would be to pull the relay(s) and test them.

Again strange that both fuses or both relays go......but it could be one went a while ago and now another has gone.

Do you have a volt meter to do more testing?

Sorry,,,,during the week I don't have much time to read/post.

 

Not a problem. Its not over heating so i'm not rushing around trying to fix it as fast as possible haha. Checked the fuses under the hood and they where both fine. How would I go about checking to see if the relays are no good? And yes I do have a voltmeter.

 

The relays are what I call simple four pin relays.

There are two pins that are the "coil" side of the relay. Means when power and ground are applied the coil will "close".

When the coil is closed this means power/continuity between the other two pins are present.

 

Had to post that first so I could keep my train of thought together.....and see the pic's.

So you can pull the relay. One of the "sockets" of the relays four pins should be hot (12v) at all times, you can see that in the first diagram I posted where straight from the battery, thru a fuse are two is always hot. This is where the power to the fans really comes from.

Next from the first pic, you can see where when the key is on/pos II there is power to the "coil" side of the relay.

So when the key is on/pos II and you then ground the cooling fan switch (I call thermo A) on the t-stat housing - where the lower hose connects to the engine. This supplies the ground to the coil side of the relay, closing it. Allowing power (12v) to flow from the one pin to the other.....in the pic, pin #1 and #2 now have continuity - thus alowing the 12v to pass to the fan.

not sure if that ramble made it better or not

EDIT: So using the pin #'s in the second pic. Power and ground to pins 3 and 4 of the relay, you should have continuity between pins 1 and 2.

 

Ahh ok now I understand how it works.That helped a lot actually. Hopefully once I test them they don't work so I could finally fix the problem haha.

 

With a meter there’s lots a ways to go about it. So just offering another suggestion you could try also.

Going strictly by the schematic both fans share that G201 ground. That’s the one simple thing I see in common.
With car off if you put one meter lead into the black wire on the connector going to the fan. Then put the other lead to a good ground (bare metal) you should read O ohms (continuity). Check each fan connector that way.

If you don’t read 0 ohms make sure you did not leave a ground wire off somewhere or damage a wire somewhere.

I doubt this is your problem but when you jumped the temperature sensor did you try giving the fan blades a slight push.

Both my fans starting failing within months of each other. Sometimes they would start sometimes not.
But if I spun the blade they would always start right up. Use a piece of wood instead of your fingers just to be safe.

Good luck

 

Or cheat....pretty sure the headlight relay is the same, swap it with one of the fan relays and see if one of the fans now works but the headlight does not.

 

Thanks for the input wagon, I did not try spinning the fans while jumping the sensor maybe ill give that a go to.
I was wondering if I was able to do that. I didn't know if the two relays where the same or not, they look the same at least so I'm going to try swapping them tomorrow. Thanks again.

 

Ok tries switching the relays and both the ac relay and the cooling fan relay seemed to be working. The headlights worked both times when I put the two different relays in.