2001 A/C diagnosis - what does it mean?

[12Ounce]

If you are talking about the two fan relays that are mounted alone on the strut tower .... they should be different ... from each other, and everyother relay on the vehicle. And on my '99, they look significantly different.

[davwha]

Have you bypassed the heater core to elimanate the possibility of a front or rear blend door that is not closing 100%, causing hot air to be being mixed with the cold?

[chasealley]

12Ounce,

I couldn't find them on the strut tower so I pulled open the relay/fuse panel under the hood, got the owner's manual out and according to them the 301 and 303 relays are for the high and low speed cooling fan. Not sure if they changed that between 99 and 2001. Maybe I missed something there.

Looking at rockauto.com they have two relays available - but they don't say which is high and which is low. Like mine, one is labelled 1,2,3,4,5 and the other has terminals 85,86,87,87a and 30. Alldatadiy only shows the 85 type relay and not the other for cooling fans. Anyone know which one should be where?

As for the blend door. The onr in the front I moved and measured the outside air temp coming through with the engine running just to verify no heat. I'll double check that with the MAX AC running at 1500RPM later next time I'm out there. I have had the blend door actuators off the car and disassembled looking for obvious failures like stripped gears. I do have a blend door code though but can't verify if it is front or back - or even the climate controls.

Anyone know about those relays which one (part number or terminal numbers) are supposed to be in the high and low positions?

[12Ounce]

daywha brings up a good point that I knew about but had forgotten about .... the beginning of blend door and blend door actuator problems (at least, I believe) is that the front blend doors warp ... and no longer seal at either closed position. Of course, they also no longer will travel the full arc ... thus the excessive load on the actuator.

So, a warped door may be the reason this year's performance doesn't match last years.

I'll try to find more info on those relays for your model.

[chasealley]

Trying to find see if that front blend door is warped could be trouble. There is no nice way to get in there - but the thermometer should verify if it is warped or not. I still have that blend door code - but I can't figure if it is front or back. Probably front because I can hear the ticking when moving back and forth.

I did have some success today. About 80F out again so I hooked up the scan tool to monitor coolant temp, idle speed, AC clutch, HIGH, MED and LOW fan speed and AC head pressure. I set the actuators to speed idle up to 1500. Put thermometer in the discharge and monitored from outside the vehicle.

I didn't let it warm up that long but the van just came from a short city trip and was at operating temp already. Discharge seemed to hang between 8 and 10 C. I went out and setup a garden hose to spray on the condenser fins and monitored the discharge temp through the glass. It is a digital multimeter with probe so I could set it up on the dash to face outward. It managed to get down to 4C pretty easily.

Now, maybe I should have run the MAX AC at 1500 RPM for a while longer before I started to spary the fins, I'm not sure, so there could be an error conducting the test on my part. But it did cool down fast with the hose running. Once I turned off the hose it seemed to stay at 4C though and didn't move back up.

The coolant temp never went over 199, and the last time I did it it stayed below 203 - far below the 224 needed to kick in the high speed cooling fan. I think the head pressure was quite a bit lower today too.

Any idea what this means? Did I perform the test correctly to start with? If so I imagine it is time to look at the coolant strength (flushed last autumn) followed by the correct coolant temperature sensor operation.

[12Ounce]

Interesting info!

You're much deeper into analysis than I've ever been, but I was always under the impression that the ac (being "selected on") commanded the rad fan to go into high speed ... without regard to engine temp. ???

Also, why is the actuator "clicking". Didn't you earlier write you had opened and inspected? Just curious. Maybe its normal and I just don't hear so good. Maybe a good idea to short-circuit the heater hoses, as suggested, just as a test.

The garden hose would probably overwhelm the engine temp. I doubt you have coolant issues. ... especially as the engine temps are low.

Except for once when the heater hose quick-disconnect turned loose, I have never replaced/changed coolant. Don't believe in it. I keep mixture about 65% and use distilled water. Used to periodically check the ph .... added a little bicarb of soda to be safe ... finally quit checking as I never really saw acidic levels. '99 .. 215K miles.

[garync1]

Yes I am wondering about the clicking as well.. I pulled my blend door motor apart and had to clean away the lube they use to find my plastic gears that were bad. Don"t think you should hear anything really only the motor itself if your right on it. Also what scanner gives you a blend door code. Just curious on that one??? My front blend door went out on my 2001 a while back,56.00 bucks from the dealer and it was called a blend door motor. Had to take the thing out first to show them. They pulled the numbers up and it came up as Blend door motor.You can hear the gears click when its missing a gear tooth because it trying to get to its correct spot. But I did find out it can get close and stop until the other teeth break off then it will keep clicking. By then you will know its the motor because you will only have warm air blowing or vis/versa.

[chasealley]

Thanks for the input guys. I guess I'll have some more testing to do pretty soon. Here's some answers to above.

The reason I say Low speed fan was on is because the scan tool monitor for low, med and high only showed Low being triggered by the PCM. And it stayed that way the duration of the test. Still pretty odd isn't it? If I remember from the service manual I think it said AC will turn the low fan on so I think that's correct.

The actuator. The scan tool is a laptop based Autoenginuity with the Ford extended software that let's you see most of the sensors and control some actuators. The blend door failure code I think is a "b" code and comes from the instrument cluster module in the van. I don't remember the code number but I think it reads "Blend door failure." I'll have to check the pinpoint tests on it. Why would it fail? Probably that gear, and not returning the correct position info in the correct time period. Mine certainly does click, not bad though. Opening the case I didn't see anything odd. I was expecting a mess. There is the possibility of rounded teeth - but didn't seem to be in the same place as the clicking. In any event, when I removed the blend door motor the blend door seemed to be in the full travel position. Of course that means nothing if it is warped so that bypass test is a great idea to check on that. I should probably also remove the motor and put a little gentle pressure on the door in both open and closed position and see if that changes anything temp wise.

For the flush - I did that as part of the Ford maintenance schedule - and because I just bought the vehicle. It was in good shape though once I got in there. I noticed there is a service bulletin out for something to do with voltage in the coolant causing problem with the PCM. I believe that came as a result of cheap coolants or metals in the water. I checked mine though and it is ok. I used Ford coolant.

Will try and get to some more tests as time allows. I should probably write this up when done!

[12Ounce]

BTW, I see there is a change in relay assignments between '99 and '01. Relay #301 and #303 were "switched power relays" for '99 ... and are rad fan speed relays for '01.

[chasealley]

Hi folks,

Been a while, but an interesting observation today.

Family parked the car outside in the sun after an in town trip today and it stayed for the afternoon. When I came out at 4pm to start it, it was 102F and the car had been in full sun since 12 noon. The nose of the van was facing the South of the house (sunny hot) and sheltered on the West by a garage (no wind).

I started the car and observed the engine coolant guage around 1/4" above cold - still.

Got out, walked around to the passenger's side and noticed an odd sound. Got down on my knees to listen - it was the high speed fan! Finally! The MAX A/C was on. I listened for a bit and after some time it went to what seemed to be mid-speed(is there such a thing?) for just a couple secs and then down to low.

MAX A/C was on, the engine wasn't at operating temp, why did the fan come on high? I suspect it has to do with the ambient air temp sensor located near the condenser. I assume that the heat built up under the hood enough that it triggered the fan, and after just a short time of running and clearing that stored heat from the engine compartment it went back to low speed.

I know the exact operation of this thing is written somewhere but I just thought I'd post the observation. It appears that the ambient air temp sensor probably plays a role in high speed fan operation regardless of engine coolant temp sensor. And, this probably confirms the fans are switching to high on my van.

[12Ounce]

MAX ac has to do with the air flow in the cabin ... it is only cabin air being recirculated ... no outside air. The inside fan will speed up on this setting ... has nothing to do with electrics ... just the air resistance being much less when only cabin air is being recirculated.

As far as the radiator fans are concerned; I would have expected the fans to be on hi anytime the ac is on ... no matter what else ... but I'm not familiar with your year model, so this may not be true. But please don't let some intermmitant condition such as burned relay contacts or loose wiring fool ya.

[chasealley]

Hi 12Ounce,

Ya, I was referring solely to the speed of the rad fans, not referring to the interior blowers.

I know I read the operation of the fans somewhere but I can't remember where.

Just to confirm, on my vehicle turning MAX A/C on turns the rad fans on low. I know the coolant temp that turns the fans to high speed is 224F. However I have to assume that ambient sensor turns the thing on when it thinks the ambient is too high. Too high for what though? Operation of electronics (some components known to fail at relatively low temps).

I know the relays are OK as I had the caps off them and tested continuity and coil resistance. Can't be sure about wiring right now. One further check would be the coolant sensor. Maybe it isn't seeing the temperature right. Hate to think about that. Last one I did had to be removed and poked into hot water of known temp and measure voltage. Hope Ford has a better procedure!