I found a mob in china who supply these modules, I have ordered two delivered to door total $59USD, I will update after arrival and test and if good will post where I got them to assist others in saving a few quid.

 

To my knowledge there's nothing special about alternator system. From other threads though it seems like a substandard battery or poor connections can cause problems. I recommend you have your battery tested.

 

Cheers swingwing I will pop a new battery in for a while and test current one

 

I received two units from China today, installed one and went to test it, engine cold not run for a day, unit connected no fan runnig good start, turned on ignition engine not running fan started and continued to run until ignition turned off after a few seconds it also stopped, this confirmed Thermo's suspicion of it being the module.
whilst this is better than the cooling fan running constantly regardless of temp or ignition status until battery would die it is not the normal operation, left to this the fan motor life would be reduced and the battery would be needing more charge potentially reducing alternator and battery lifespan due to working harder than needed, obviously the fan should only be on when the temp requires reducing.
I have emailed the company with queries and awaiting reply, will post when I get it, till then at least I can use the car without having to keep connecting and disconnecting the fan power lead

 

ok I have tried the second sample unit I bought from China, same result as first not suprisingly, fan comes on and stays on with ignition on goes off when ignition off which is better thenon all time regardless but not ideal, manufacturer says they have sold many with no problem and don't know what reason could be so one step forward and sit down, anyone had this occurence ??

 

I have tried two new modules from china (bought as samples) what I get now is both fans come on with the ignition and stop a few moments after igniton is turned off again. the engine is stone cold, gauge reflects that and gauge comes up to norm as engine is run to temp, I have replaced top hoses while replacing the unit as they were collapsing as engine cooled, I have bled system and everything is normal apart from fans operating with ign on, the original issue was I got home one day and noticed the fan was still running after I had been home for an hour so I was having to disconnect the main plug each time I left the car and re-connect when I wanted to use it again otherwise I would have a dead battery.
its very strange all I can think now is engine control module issue but code reader says no codes recorded although the screen says $03 $07 & $0A the o3 was the forward O2 sensor which I have replaced the $OA is normal the 07 apparently has no meaning weird
any ideas guys I can't find anything else as a culprit

 

Wayne, I would be curious what voltage you are getting when you attach a multimeter to the white wire with a blue stripe going to the fan module. This wire is coming from the ECU to tell the fan module how fast to spin the fans based on cooling needs. If the motor is cold and you have the A/C-heat turned off, then the voltage should be essentially 0 VDC. If you are getting say 6+ VDC, then your problem is more the ECU, not the fan controller.

 

Thanks Chris I will check Volt right away.

 

I have checked Volts, on the main block connector there are the two main power lines then two smaller wires one white with green trace the other white with blue trace.
Engine cold A/C & heating OFF . ign OFF 0 volts to both, ign ON white/blue gets 0.02v and white/green gets 12.1v and as before ign ON both fans ON and at full speed I think.
0.02v seems too low to trigger to me certainly no 6v+ on this w/b wire Ign ON, so does this look like ECU? is the only fix to try a replacement? (costly?).

 

Wayne, if the white/blue wire is giving you 0.02V, then that should be telling the fan modules not to run. So, your fans running are a sign of the fan modules not doing what the ECU is telling them too. So, your "problem" is still in the fan module. The issue now is that the fans run any time the car is running which is not necessarily an issue, but it can potentially have a slightly negative effect on your mileage (say 0.2 mpg or so).

 

hi Chris,
Thanks for feedback I thought I might have gotten faulty units from China, I shall let them know the results and what you have told me to see if they have had any other reports, looks like I will have to go with genuine module to confirm.
thanks again, at least the china version means I can use the car till I sort it out.
cheers,
Wayne

 

Hi forum,

I am experiencing the exact same behavior (more on this below) on my 2002, 2.5, auto. Here is what I have done so far to run the problem down:

• Battery check
• Replaced fan control module with 2004 unit
• Thermostat replaced (but not ruling this out as I have no faith in the mechanic who replaced it)

Prior to replacing the fan module, the car would warm up before the fans came on but run at near-full speed until I turned the car off.

After replacing the fan module, the fans come on a few seconds after I start the engine, but run at varying speeds depending on whether I'm stopped or moving (mid-speed fan speed, low-speed fan speed, respectively). However, regardless of fan control module, the fans still run non-stop regardless of outside temperature, or the air conditioning being on or not on.

After witnessing this behavior my new independent mechanic (Jag specialist) told me the fans should not run as I've described and he suspects the thermostat.

I'm not convinced it's the thermostat but my car is in the shop now and I'll have an update Tuesday or Wednesday.

My 2-cents.

 

Jag4, just to keep in mind, the fans may run if you have the heater set to defrost too. The defroster uses the A/C system to remove moisture from the heated air by allowing the incoming air to pass over the A/C coils, pulling the moisture in the air out. This is where I would tell you to make sure that the A/C-heat is turned off completely, then see what the fans do. If you turn the A/C on to max, this will cause the fans to run at max speed, regardless of engine temp. In other conditions of the car, the fans will run at a speed that the computer thinks is needed to maintain either sufficient air flow for the A/C system and/or sufficient air flow for engine cooling.

If you are wanting to do a check yourself, you can put the instrument cluster into a diagnostic mode (if you need instructions on how to do this, let me know) and then hit the trip button till you see "XXXX C" (where XXXX is 4 numerical digits). When you first start the car, it should read around "0230 C" (or 23.0C, or about 70F). In this state (assuming the A/C-heat is turned off), the fans should not run at all. As the temperature climbs to near "0950 C" (95C, or 195F), the fans should be moving in a medium speed, causing the indication on the dash to reach a steady state. You may hear the fans speed up and slow down slightly to maintain this indication. As the indication approaches "1000 C", the fans should be running at maximum speed to lower the engine temp.

 

look forward to hearing what the shop tells you Jag4

 

Thermo, Great details. Makes me think about the fact the rear defrost hasn't worked right from the get go. We'll see what my guy comes back with before running down the defroster rabbit hole. In the meantime, at least the fans are running.

Cheers

 

Me too!

 

"Thermo, Great details. Makes me think about the fact the rear defrost hasn't worked right from the get go. We'll see what my guy comes back with before running down the defroster rabbit hole. In the meantime, at least the fans are running."

Jag4, Thermo isn't talking about the rear defrost, he is talking about the defrost setting to the front windshield. When that is on the A/C is on to take the moisture out of the air. So, if your rear defroster is not working, that is an entirely separate issue

 

Alfadude, Thanks for the clarification. I miss understood. Tks!

 

WayneinAus, My mechanic isn't sure what the problem is. To be clear, he didn't spend too much time on it since I really asked him to do the brakes. So this is still an issue. He did check the thermostat which was fine.

Like I said, I just swapped out the old module 2002 fan control module for 2004 OEM module, and now the fans come on about 15 seconds after the car starts.

I'll be looking through the previous threads and electrical diagrams and begin testing.

The car is running better than ever, but still these damn fans running in the background. It's annoying as heck.

 

[QUOTE=Thermo;1646346]Jag4, just to keep in mind... If you are wanting to do a check yourself, you can put the instrument cluster into a diagnostic mode (if you need instructions on how to do this, let me know)QUOTE]

I'll PM you.