[atoner]

There is a signal for under 35 mph for the airbags.

Any idea where I can tap into this, preferably in a buffered location such than an issue with my modification won't interfere with the air bags? Thanks.

 

[jpn6438]

Just bought my 07 ex-l about a month ago. When I stop, idle and going slow my a/c just blow air. When driving the a/c is ice cold. When in park i pop the hood and the condenser fan is not even on. I can hear the fan trying to come on at idle and park. Will this mod work in my case? A friend mention that the fan clutch might be going out.

 

[atoner]

Just bought my 07 ex-l about a month ago. When I stop, idle and going slow my a/c just blow air. When driving the a/c is ice cold. When in park i pop the hood and the condenser fan is not even on. I can hear the fan trying to come on at idle and park. Will this mod work in my case? A friend mention that the fan clutch might be going out.

If working properly, I believe a stock '07 Odyssey should have both fans behind the radiator cycling on low-speed when the A/C compressor is on. If both of your fans do come on low-speed with the AC compressor and you're still having barely cool air when your Odyssey is stopped or going slow, this mod will help.

If you only see one fan coming on with the compressor, then you might have an issue with that fan or a relay. Do both fans come on high-speed if you let the engine warm up until the radiator needs air across it?

 

[cnn]

Just bought my 07 ex-l about a month ago. When I stop, idle and going slow my a/c just blow air. When driving the a/c is ice cold. When in park i pop the hood and the condenser fan is not even on. I can hear the fan trying to come on at idle and park. Will this mod work in my case? A friend mention that the fan clutch might be going out.

The basic minimum is: replace all 3 black relays, $4/each at dealer = $12 total.
The fan relays probably fail.
Also, the AC relay, when flickering, can cause Clutch to slip.
See the long thread on "05 AC Clutch troubleshooting".

 

[Floyd]

This is good info guys. I just had my "condenser" fan break on me and now after I installed the new one I havent seen it come on once even with the A/C on max.
The "radiator" fan comes on but the other one on the passenger side is just sitting there.
I guess an easy test would be to jump the relay and if it fires up then a new relay it is. If its not kicking in ill have to meter it out and figure out where im loosing my power to the fan.

 

[autobot152]

I would still love to find a way to make the fans come on high only when I'm stopped or, ideally, my vehicle speed is below ~30 mph. I haven't put much thought into this, but I wonder if there's a signal I could tap into. I'm guessing I could somehow get to the park signal from the shifter.

I've also noticed the headlights dim a bit when the fans are cycling due to the high instantaneous current drain. This may be another reason, in addition to fan and relay longevity, that Honda didn't bring the fans on high with the AC.

How about utilizing a shift light? disabling the mod when the RPM is above a certain threshold.

 

[stevescivic]

So some suggestions on how you can modify the fan control to be fully automatic and "self aware" of it's surroundings.

I would imagine that we'd want to only active the fans on high when:

1. Vehicle speed is below say 25 MPH
2. Ambient temperature is above 85F

Materials needed to meet the above mentioned requirements:
1. User configurable ambient temperature switch (much like a thermostat). When temperature reaches above 85F then it closes the circuit to put the fans into high speed continuous mode
2. Air velocity sensor or switch. In the HVAC industry there is a switch called a "sail switch" that closes or opens a circuit if there is sufficient airflow. I would imagine that in our modern world that there would be something like that for measuring how much air is passing over the switch and open and close a circuit accordingly.

Just throwing out some ideas...

 

[jpn6438]

Before I replaced the relay, only the radiator fan come on when the van is in idle/park and the condenser doesn't. Went to the dealer and got 3 new relay. My dealer charge me $10 a pop. Replaced the relay and both fan came on while in park. That last about 30 second and the condenser fan stop (meaning there is a short somewhere to burn out the relay). Put the old relay back in it original place. Put one of the new relay into the low speed fan location (forgot which was the bad relay) and turn the a/c on. Again both fan work for about 30 second before the condenser fan went out. Turn the van off to put the original low speed relay back in. Rurn the van on and now both fan is not working. Hopefully I can get another relay for the radiator fan and that would solve at least one issue and let a mechanic trouble shoot the shortage of the condenser fan relay.

 

[stevescivic]

jpn6438 it could be related to a bad motor winding in the condenser fan as it is the one that keeps crapping out on you. I would say that you should consider trying to replace or at least swap out the fans with a known good working one and see if that resolves your issues.

 

[cnn]

Before I replaced the relay, only the radiator fan come on when the van is in idle/park and the condenser doesn't. Went to the dealer and got 3 new relay. My dealer charge me $10 a pop. Replaced the relay and both fan came on while in park. That last about 30 second and the condenser fan stop (meaning there is a short somewhere to burn out the relay)...

Some tricks...
- Very easy to confuse the relays (old vs new), so use a sharpie to mark them before playing around with them.
- On the relay, there is a marking for the date of mfg, so you can use it to know which is old and new.

- Re condenser fan, search for posts by "Floyd", I believe his condenser fan disintegrated (plastic fan blew up), punching a hole in the rad ---> engine overheated ---> had to replace head gaskets ---> $$$.
But I think Floyd has more than 200K miles.

So if you have more than 200K miles, consider replacing both of these fans as they have worked a long time and can blow up any time. I know these fans cost some money, but they are still much cheaper than a head gasket job.

 

[cnn]

Re date of mfg...
If you look at the photo I posted above, the factory relay has this marking:
1917A12 O, I think the relay was mfg'd on ? 191 days of 2007.

I am just guessing here because when I bought brand-new relays recently, the fourth digit was a 3, which is 2013.

 

[Floyd]

- Re condenser fan, search for posts by "Floyd", I believe his condenser fan disintegrated (plastic fan blew up), punching a hole in the rad ---> engine overheated ---> had to replace head gaskets ---> $$$.
But I think Floyd has more than 200K miles.

Yea Ill have to post those pictures up. Just got it back on the road but its nuts that a fan letting go could have a chain reaction to blow the head gasket. With working on it a little a night it took about a week to tear down and clean/prep and only 4.5 hours to reassemble!
I still havent seen that new fan kick on. I think the relay or fuse blew because the old fans shaft was basically welded to the motor.

 

[atoner]

It looks like I might have had a compressor problem all along and didn't figure it out until I got some gauges and looked at the service charts.

Although the low-side/suction pressure is fine, the high-side/discharge pressure seems capped at 200 psi. It hasn't gone higher despite the ambient temp now being above 80F and adding refrigerant to bring the low side pressure near the high end of the range. Discharge temp is also in or above the high end of the expected range. The diagnosis suggests a faulty internal compressor leak or discharge valve.

Once I read the service info, it became clear that the fans should have been turning on high without my mod. When temps are above 85F, the discharge pressure should always be above the 221 psi needed to trigger the high-speed condenser fans. In addition, I did get the software update to fix the PCM issue with the high-speed fans.

 

[ponju1]

you can use the brake switch to trigger hi speed rad fan. I used this trick before on my 2002 to cool down the radiator during traffic.

 

[skimask]

you can use the brake switch to trigger hi speed rad fan. I used this trick before on my 2002 to cool down the radiator during traffic.

Oh...I like that...plain and simple...I like that a LOT.
I've got a '77 Olds Starfire with a built up Buick 231 in it with twin electric fans.
On really good and hot days, sometimes the switch kicks in a hair bit too late and by the time the fans do start running, it's a loosing battle between the radiator and the water temp.
I'm gonna wire this up immediately, if not sooner.

 

[atoner]

I finally had to replace the compressor. The clutch wasn't engaging and measured an open circuit. One local shop wouldn't do just the clutch, and another claimed the clutch circuit was an open going through the compressor. After the repair, the high-speed fans are turning on automatically without my mod.

One hitch is keeping me from wrapping this story up with a nice bow. I measured the high- and low-side pressures after the repair, and the high side was just barely above 200 psi despite the ambient temperature at 98F and the high-speed fans on. It turns out my gauge dial was bent and getting caught on a screw right around 200 psi. After I fixed that, the pressure went up to 300 psi and tracks inlet air temperature. So now I'm wondering if my pressure from before was capped around 200 psi due to the compressor or the bent gauge. On one hand the high-speed fans never came on automatically, which says the pressure wasn't getting to 221 psi. I also believe the PCM code update was applied back in ~2008. Today I also got the VSA and fuel pump recalls done, but I don't think they included a PCM update (in the event the old update wasn't applied).

 

[Jrprock79]

There is a bulletin with a PCM reprogram that addresses this problem.

Basically it still runs the fans on low speed until the high side pressure hits a certain pressure and then it switches the fans to high speed.

 

[Jrprock79]

Here you go

 

[surgeon]

Is there a way to test this issue to see if it is correctly working on our vans?

 

[John Clark]

Bring your van up to operating temp and let it idle with AC off. Both fans should cycle on and off (or just run on low speed if it's really hot out.) That will test the low speed circuit.

Then turn on the AC. After 30 seconds to a minute BOTH fans should kick on to high speed (happens at 221psi on the high pressure side of the AC so your AC system must be serviced and working correctly.) I've seen a lot of reports of radiator fans (the one on the driver side) having blown fuses which will cause the radiator fan to turn off when high speed is called for but work fine on low speed. This is because at low speed both fans run off the condenser fan (the fan on the passenger side) power and relay. I'd like to know what causes the radiator fan fuse to blow but replacing the fuse seems to solve the problem. I found mine blown and replaced it a couple months ago and it's been fine ever since. I've been checking the fuse once a week because I still don't know what caused it to blow in the first place.