A/C Cooling fan (1 Viewer)

[sasok]

Dear All,

I have a problem with the cooling fan of the A/C radiator in front of the car: The fan is good as I tested it with separate power line from the battery, but it is not getting the signal from it's relay to start.
This problem causes that the A/C is not cold when the car is in heavy trafic.

Did anyone ever had this problem?

Thanks for your help...

Sasok

 

[e9999]

You're talking about an electric fan in front of the radiator at the very front of the truck between the headlights, right? Anyway, is there a fuse maybe? Did you wiggle and reset all the connections? Check the ground? Can you see power getting to the relay (check with a voltmeter) and out? Maybe you can borrow a relay from somewhere else in the truck (of the same rating) and give that a try?

(edited for likely error)

 

[sasok]

In fact my car is a 2000 model from the US, and I brought it in Mozambique. It's this same fan that you are talking about, but I'm unable to find the relay. Could you please tell me the name of the relay and I can find it? All fuses are OK...

Thanks

 

[sasok]

Exactly I'm speaking about the blower assy part number 88590-60030 that is not getting the signal from it's relay... But impossible to find its relay.

 

[e9999]

well, I think I was wrong about the fan, I don't remember seeing it on my truck but it's been a while since I looked at that one. Strangely it doesn't show in my FSM a/c component list. Maybe a function of year. Anyway, I'll correct the post above.

Did it ever work or did it stop working while you already had the truck?

No idea where this relay would be. Check the main relay boxes? Can you follow the wires? Or check a Factory Service Manual, there are some on the web I think. Presumably there is also a temperature sensor or a connection of sorts to the a/c system that would control the fan via the relay.

 

[CappyKD]

I have been wondering about my electric AUX fan for a while. I have never seen or heard it run, even in summer with the ac on max. Coolant temps stay good, but.........

 

[hoser]

My 98 has one and so does Spresso's 99. AFAIK, newer US 100's don't have it, could be '03, I don't know. FSM says fan will turn on when refrigerant pressure is greater than 220psi. Check that first, then check pressure switch and lastly the condenser fan relay.

 

[e9999]

Sasok: the compressor is otherwise running fine when you have the a/c switch on, and it's only under high loads / low speed that the air is not cold enough, right?
Give us a bit more info?

 

[sasok]

Yes, the compressor is working well : when the car is at high speed, the cooling is very good. Only when the trafic is heavy it's getting much less cold.
You spoke about temperature sensor, could you tell me wich part number you were meaning? Is there a way to test this sensor?

 

[sasok]

How to test pressure switch , and where to find the relay?

I think you are right but I don't know how to proceed...
Do you think the temperature sensor part number 88625-32170 is the one commanding the relay?

 

[e9999]

if you have access to gauges you could first check what the pressure is on the high side as Hoser suggested. That is very easy to do and if too low (maybe due to a slow leak) might explain the lack of fan running, given the above 220 psi criterion. I don't know if there is a specific pressure switch for that, but if the a/c is working well most of the time, and still some at low speed, at least the main a/c pressure switch (the one that would stop the whole system if the pressure is too low or too high) is probably OK I would think. Naturally, the fan would not work if the relay is busted.

But I'm just guessing, best to find -or talk to somebody who has- an early 100 FSM to check for tests and parts location and function. Which I would think is a good idea to have in Africa anyway.

 

[hoser]

I believe the pressure switch <88645‑60030> commands the relay. In the picture I posted, it might be located in the lower right hand corner of the oil cooler. Not sure if it is normally open or closed.

 

[100 TD]

IIRC, the units with the fan had a triple range pressure switch. Most have dual, low pressure cutoff if you loose refrigerant, high pressure cutoff to protect compressor. The triples have a medium range to bring the fan on, it's all in the one pressure switch on the refrigerant line.
Look for a 15A CDS Fan fuse, CDS Fan relay, I expect the relay may be mounted on a little bracket next to the main fuse block or could be in the main fuse block. Part number may be 88630-60150 or 60090, or 60091. Wiring to the pressure switch it appears that the switch, switches to ground to activate the relay, the Black/Red stripe wire to ground should activate the relay.

 

[e9999]

triple? interesting. But again, doesn't the fact that the compressor is running suggest that the switch is likely OK?

Well, I was right, our 03 does not have the fan, I just checked. Which suggests they must have changed something to the other fan or the rad when they eliminated the front fan sometime between 2000 and 2003, since you are having trouble when the fan is not working. Or there is something else wrong with your system.

 

[trackmur]

My 2001 will only operate the electric fan when the refrigerant is fully charged. With some loss of charge over time, the AC will still function but the fan will not engage.

 

[sasok]

OK, first I'll charge the refrigerant then will let you know...

 

[CappyKD]

triple? interesting. But again, doesn't the fact that the compressor is running suggest that the switch is likely OK?

Well, I was right, our 03 does not have the fan, I just checked. Which suggests they must have changed something to the other fan or the rad when they eliminated the front fan sometime between 2000 and 2003, since you are having trouble when the fan is not working. Or there is something else wrong with your system.

With 2003 they redesigned the radiator for better cooling... (According to the FAQ) That must be when they eliminated the Aux Fan.

Hmmm triple range switch.... I guess I'll have to check the refrigerant pressure.

 

[e9999]

ah, check this out, from the "new features" of the 03 manual:

"15. Air Conditioner
A seal and a baffle plate that prevent the detour of warm air from the engine compartment has been adopted
to improve the cooling performance. Accordingly, the electric fan that was provided on the ’02 model has
been discontinued. As a result, a reduction in weight and fan noise has been achieved."

so yes, the fan loss was for the 03s.
Interesting also is that this again reminds us that seals (presumably as in around the shroud etc) are important for good cooling. No idea what that baffle plate is though.

Here is another interesting tidbit:
my 03 manual states that the high side pressure should be around 199-213 psi (14-15 kgf/cm2) under the usual conditions, which is less than the 220 psi mentioned above. That is inconsistent. Did the pressures possibly decrease also after the fan loss?

 

[CappyKD]

Hmmmm.

 

[hoser]

Here is another interesting tidbit:
my 03 manual states that the high side pressure should be around 199-213 psi (14-15 kgf/cm2) under the usual conditions, which is less than the 220 psi mentioned above. That is inconsistent. Did the pressures possibly decrease also after the fan loss?

Is it inconsistent? 98-02 Fan kicks on when pressure exceeds 220psi... isn't that saying the pressure is normally less than 220psi?... like maybe 199-213? =)