A/C fan runs when I pull fuse???

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Hey y'all -

OK, very weird behavior. My a/c fan hasn't run for a long time. I even bought a new dual fan unit, and have been intending to replace them.

However, recently reading something somewhere someone said, "trying pulling the fuse."

So, I pulled fuse 16, A/C clutch, after-run coolant pump. It's one of the small 10amp fuses on the top row, second from the right.

Immediately the fans starting running!

The fuse looked a little corroded, so I replaced it with a new one. Immediately the fans stopped running!

WTH?

Can anybody please help explain this behavior?

Thanks!

Jud.
 

ToxicDoc

Veteran Member
Joined
Mar 1, 2018
Location
Virginia, US
TDI
2001 Jetta, S7, .216
VW is unusual in that removing a fuse can actually trigger some systems. The fans will trigger on if the fuse is out or blown. What you are seeing is normal behavior. You have to look elsewhere for the AC problem. The good news is that it sounds like your fans work.
 

Mongler98

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Mar 23, 2011
Location
Northern MD (HAGERBUSH)
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98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
^^^ ahaha, ah yes, the joy of VW engineering ^^^
So what exactly are the symptoms of your AC issues? everything works and blows cold just the fans dont kick on?
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
Yes Mongler98, that's exactly right. Works fine, blows cold, fans don't kick on.

I don't understand why putting a good fuse back in turns them off. So weird.
 

Mongler98

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Joined
Mar 23, 2011
Location
Northern MD (HAGERBUSH)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress)
Yes Mongler98, that's exactly right. Works fine, blows cold, fans don't kick on.

I don't understand why putting a good fuse back in turns them off. So weird.
something to do with signal, dont worry about it, i dont understand either but i have seen it plenty here, search for pulling fuse 16 on these forums if you care

if its working fine, leave it be. ac fans dont always come on, it should when its hot AF outside and there are a few things like ambient air temp sensor and the fan relay that could cause a no run but pulling that fuse means that it should be working properly. im not 100% on this one but yea, at least its working!
 

gforce1108

Top Post Dawg
Joined
Aug 2, 2006
Location
Newburgh, NY
TDI
04 Jetta GLS BEW, 14 Audi A7 V6 TDI
A blown fuse 16 has confused many people with fans that stay running. Someone here listed exactly what it does but I can't remember. I just know the first thing to check is F16. I have even seen it in person - a buddy was testing fuses and put 16 back in the wrong location.
 

Judson

Veteran Member
Joined
Jan 18, 2001
Location
Cheyenne, WY
TDI
2001 Jetta
So I yank it and leave it out?

Okey dokey no skin off my back for sure! I will keep a spare in the car, though, just in case.

Thanks!
 
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