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Discussion Starter · #1 · (Edited)
So I took my beast to my parents home to top up its AC gas with my father's filling equipment. I ran the AC using the MAX button for about a few minutes and then at lower speeds for 10 - 15 minutes tops while we topped up the gas. It was all fine and dandy.
Later on my drive home, the cosmic irony hit and my AC's fan refuses to spit anything out from the vents. It was completely dead. Tried again and again. Low speed, max speed, nothing. Not a single peep from the AC unit except for the vanes moving about when I change the recirculation & air direction settings. No squeaks from the motor or any bearing sounds. I knew my FSU was gone ... or so I thought.

After spending a good time working under the dashboard (and coming up with two new pages of profanity combinations in the process) I finally wrestled the FSU out from its wiring.
Going online to check its details, I was surprised to discover that its not he original faulty FSU component (metal encased GKR manufacturer) that is reported in the Bimmer Fest forums: What is the right brand of FSU (aka FSR) final stage resistor/unit to buy for the E39 - Bimmerfest - BMW Forums

In fact, my FSU is the Sitronic/Valeo model that was recommended in the forums as a reliable replacement!

Upon closer observation, I noticed that there was a tiny spot of melted plastic at the base of one of the contact pins on the FSU. Using a small screw driver I also scraped the little bit of melted plastic and what looked like metal oxidation stuff off that pin and returned to the car. Studying the wiring plug in the car, I too found a small portion to have melted plastic. Hinting at why it was so difficult to seperate them in the first place.
I checked the 2 hidden blower fuses under the dashboard and confirmed they are both in perfect condition before plugged the FSU unit back in and, lo and behold, my AC blower was up and running again.

Has anyone experienced this weird problem before? Is that pin supposed to run that hot till the plastics are at risk?
Do you think its a good idea to clean this unit's pins and continue using it or to get a brand new FSU?
 

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Do you think its a good idea to clean this unit's pins and continue using it or to get a brand new FSU?
What's that saying?... Pray to god, but row towards shore: I'd probably fix it and button it up, BUT also order a new FSU to have on hand.
 
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