So I have a new to me A6 4.2l sedan. I recently completed the transmission rebuild. I noticed that while driving A/C blows warm. I read ALOT about possible problems. I noticed that neither fan ever turned on. I checked both with 12v directly to them. Pass side outward pusher worked, driver side inwards puller didn't. I bought a replacement so I know both work.
I have read considerable about the fan control module being suspect. I bought a used (supposedly tested good) replacement. I know that fan control unit gets battery voltage after relays and fuses. I tested and my fcm is getting like 13v with car running at its power plug. Each of the two fan outputs from the fcm are putting out 11v when car is hot , coolant at like 200°f. No fans running. Now if I jumper the four pin thermo switch from the lower radiator hose, both fans run on low and high.
My questions are...
1. At what coolant temp (in °f) should the aux cooling fan turn on.?
2. If I jumped the terminals to simulate a closed thermo switch, and the fans came on, doesn't that tell me my fcm is good and the switch is bad?
3. Could someone test a known good fcm? I'm curious if 11v at idle normal output for the fan leads.
Hope this made sense.
Fear not the Diy!
Bratcop
Sent from my LG-US996 using Tapatalk
I have read considerable about the fan control module being suspect. I bought a used (supposedly tested good) replacement. I know that fan control unit gets battery voltage after relays and fuses. I tested and my fcm is getting like 13v with car running at its power plug. Each of the two fan outputs from the fcm are putting out 11v when car is hot , coolant at like 200°f. No fans running. Now if I jumper the four pin thermo switch from the lower radiator hose, both fans run on low and high.
My questions are...
1. At what coolant temp (in °f) should the aux cooling fan turn on.?
2. If I jumped the terminals to simulate a closed thermo switch, and the fans came on, doesn't that tell me my fcm is good and the switch is bad?
3. Could someone test a known good fcm? I'm curious if 11v at idle normal output for the fan leads.
Hope this made sense.
Fear not the Diy!
Bratcop
Sent from my LG-US996 using Tapatalk
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