Lately i have been in the process of trying to fix my non-working A/C system in my TDI. After researching it and narrowing it down to the solenoid or the fan assembly. I went ahead a swamped the solenoid within my compressor, as so many people suggested. My A/C still does not work. It works when my car is running down the highway, having airflow through my front end. I know now it is my Front AC fan assembly that is not working correctly, BUT after running into major traffic jam. I sat idling for multiple minutes. Painfully inching along the highway. After several miles, my eye caught my temp gauge showing above average temp. After several minutes my gauge continued to climb. After growing extremely hot, i was able to start moving again, luckily in traffic to get some airflow in my car. Dropping the temp back to normal in a matter of 2 minutes. I now realize. BOTH my fans are out, in my TDI. I have read on other posts that the fan assembly are tied together, which would make sense for my case. My question, is there any good way to test Fan assembly? Instead of spending 200-150 on new fan assembly. I have read it can also be the Fan control Module (FCM). I want to diagnose which component is shot before i buy the wrong one. Which i have done, so many times.
BRM TDI: Radiator Fan/FCM Test? diagnose bad
- Thread starter DunnTDI
- Start date
oilhammer
Certified Volkswagen Nut & Vendor
There is no FCM on that car. It is integral with the left cooling fan.
And quality fans cost more than $200. The Chinacool ones (if they even fit) are usually short lived garbage, and sometimes they come apart and take out the radiator.
Chances are one fan has been dead for a while, and now the second one finally died. However, if you want, you can take the assembly out, unplug the right fan from the left, and apply power and ground directly to it to see if it works. Then you'll know the problem is in the left fan alone. If it does NOT work, then I would plan on replacing both fans.
And quality fans cost more than $200. The Chinacool ones (if they even fit) are usually short lived garbage, and sometimes they come apart and take out the radiator.
Chances are one fan has been dead for a while, and now the second one finally died. However, if you want, you can take the assembly out, unplug the right fan from the left, and apply power and ground directly to it to see if it works. Then you'll know the problem is in the left fan alone. If it does NOT work, then I would plan on replacing both fans.
Well that is good to know. Is there a brand that you would say is better than others? And after checking the fuses, is there any other things that could cause the fan assemblies to stop working? that I could diagnose? or on the VW 06 MKV model is that the only thing that could possibly fail?. I also read, (Correct me if im wrong) that the two fans are tied in series together. So if my first fan failed, my second fan would then not work also.
oilhammer
Certified Volkswagen Nut & Vendor
From my experience, I would just go to Volkswagen and get them. They likely have them on the shelf. Pretty common. The newer ones are improved.
Finally had the chance to open up my fan assembly. I previously bought VCDS around December and tried manually testing the fan assemblies but no luck. So finally today, i got around to yanking the assembly off and opening up the larger fan. I had read on other forums that the brushes could stick. Wanted to see if that was the culprit. Sadly when i finally mangled the thing to death got it apart and found the brushes still touching. So I dont understand what could have gone wrong on it. You said it is integrated into the left fan. Could that have been the issue. Bad FCM?
theroyztdi
Member
I have the same issue but have not got around to testing it yet. I ordered a new smaller fan online before I realized that neither fan was working. I was going to cut the back of the fan motor off to check the contacts but I may just get a new one and be done with it.
Gave in and ordered two new fan assemblies. Mounted them and plugged them in. Cranked up my car and pushed A/C button. No Luck. Fans do not spin. Even waited till engine was completely warm and still no luck. Checked fuses multiple times. Tried hooking up VCDS got this:
006470 - Control Module 1 for Coolant Fan
P1946 - 000 - Defective
This is after purchasing new fans. Not quite sure what needing to chase next. Was looking for exact description on Ross-Tech site but no luck on control module 1 for coolant fan.
In summary, I have replaced the compressor Solenoid and now both fans. No Luck. Only thing i can think of is a possible broken wire/short.
006470 - Control Module 1 for Coolant Fan
P1946 - 000 - Defective
This is after purchasing new fans. Not quite sure what needing to chase next. Was looking for exact description on Ross-Tech site but no luck on control module 1 for coolant fan.
In summary, I have replaced the compressor Solenoid and now both fans. No Luck. Only thing i can think of is a possible broken wire/short.
MDK22
Member
Just an fyi the terminals for the fan like to corrode. you need to file them down with a terminal file kit or a screwdriver wrapped in sand paper. I am talking the main ones with the big plug next to the radiator. To inspect them you need to jam a screwdriver into the female end and use a flashlight. Female end is harness side so replacing the fan assembly would not fix. Sry haven't been on here in ages.
MDK22
Member
Relay is built into the module on the back of the fan. You have to apply power and ground to small pins to be able to ohm the big pins. This is once again at the connector only this is fan side. So 9v battery to small pins and ohm big pins. Only reason I know this is I had the exact same issue you are having.
I opened up the connection, and all the terminals look extremely clean. No sign of corrosion anywhere. I did cut the old connector off my original large fan and plugged it back in to the female side of radiator connection as a pig tail. I then took my multi-meter and read values off of different lines. My readings were extremely interesting. Am trying to post pictures but not having very good luck. However using the four wires coming off of pigtail (color(size dia)): RED (large) , BROWN (large) , BLACK (Small) , GREEN (Small)
1) with the car off - my multi-meter was reading 6.49 V across RED and BROWN.
2) When the Car was turned on - RED and BROWN was reading 7.54 V.
3) From BROWN to BLACK was reading 14.25 V
4)From RED and Green was reading 7.64 V
5) from RED and Black was reading very low around 0.58 V and similarly with BROWN and GREEN
1) with the car off - my multi-meter was reading 6.49 V across RED and BROWN.
2) When the Car was turned on - RED and BROWN was reading 7.54 V.
3) From BROWN to BLACK was reading 14.25 V
4)From RED and Green was reading 7.64 V
5) from RED and Black was reading very low around 0.58 V and similarly with BROWN and GREEN
So read resistance across big pins also?
Finally found the issue. Started checking continuity on wires running to my main fans assemblies. Had good connections. Started running it back into main power and ground following back to the fuse box. My inline Fuses were visually fine. But after checking continuity, my one bolt on fuse, along the side of the fuse box had been blown. After re-installing fuse, fans operated as normal. Its amazing how cars can humble someone!