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Discussion Starter · #1 ·
Hi, I'm new to the group. My partner and I came into a 1.8L turbo manual 2002 beetle for free!

It needs a bit of work but two things first.

1) I'm looking for knock sensor 1, I had the check engine light come on and it was that code. Is it this nut with a little yellow paint on the front passenger side of the engine? I'm not exactly sure what I'm looking for since I don't have the replacement part yet.
https://photos.app.goo.gl/dw15QWDrDuyEPcYV9

2) Blower fans don't work, so the AC is not useful in this very hot July weather. I was able to put a new fuse in, the fans and ac seemed to work for a minute and then they cut off. It wasn't that the fuse was blowing, it's the base of the fuse in the fuse box where the actual short is and it's causing it to melt.

So, I'm looking to bypass the fusebox all together, cut the wire to the blow fan, add my own fuse in the line, and go from there. Below is a photo looking behind the fuse box. Any suggestions? Not sure how I can trace the wires packed that tight.
https://photos.app.goo.gl/SA7KikN5N26ojqn29
 

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I can't help you with the knock sensor but the fuse box (on top of the battery) melting is a common issue I'd suggest checking/replacing the box: https://www.youtube.com/watch?v=Fmsh89j6OY8 <- Looks pretty easy to do.

Use https://parts.vw.com/and your vin number to get the right part number.


There is a way to bypass the fusebox and wire it directly to the FCM (fan control module) but I can't find that page and the past owner of my car (08 2.5L only 1 radiator fan) did it wrong so the A/c only has power when the radiator fan kicks on (87C~ coolant temp?) so IMO it's worth spending money and fixing it right.
 

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You might acquire a vw specific scan tool and that may provide you with factory vw trouble codes, that could narrow down the problem, help you figure things out (many cheap chinese vag scanners on amazon, obdeleven for handheld devices like a phone or tablet and finally VCDS by Ross Tech, that runs on windows based pc's, portable devices).

First of all, for the knock sensor; be sure, to post any trouble codes you are getting and always use, the Ross Tech Wiki, to look up the code definitions. If the engine, has sound loud noises; from other issues, it can possibly give you a false positive on the sensor but you need, to confirm the meaning of the trouble codes and do some testing to diagnose the problem.

knock sensor locations:

https://workshop-manuals.com/volksw...knock_sensor/component_information/locations/

testing and inspection:

https://workshop-manuals.com/volksw..._and_inspection/with_manufacturers_scan_tool/

There are known issues with a/c and the cooling fans; because of wiring problems, low speed burned out in the radiator/cooling fans or the fuse box, being melted or the fuse holders, not having a good connection. You might try cleaning the connections with sandpaper, a small wire brush and cleaning them with electrical contact cleaner (e.g. QD® Electronic Cleaner, 11 Wt Oz - 05103; available at most home improvement, auto parts stores and places like Walmart).

It maybe a good idea, to remove the fuse box and visually inspect the connector/fuse socket for damage and replace it, if necessary. Please do not rigg and modify the stock system; diagnose the problem and repair the system correctly, then things will work as it should, things will be easier to deal with in the future (many "riggs", while seeming to repair a issue; tend to cause more problems in the future). Many, tend to "fix" the symptoms of the problem; rather then, dealing with the primary issue, causing the melting problems. We have seen, a number electrical issues with connections getting corroded; from water ingress, corrosion and this can result in overheating of connections, as corrosion will cause resistance and scorching of wire insulation, connections, terminal ends, fuse boxes, fuse holders, etc.

Fix it once and fix it right; use high quality oem or genuine vw parts and you typically, will be rewarded with good repair results and a reliable solution, that will make your car more reliable, in the long run. VW offers repair terminal wires, fuse boxes, connector housings and other electrical repair parts, if needed.

If the fuse box on top of the battery; is melted, aftermarket brands Motor King, Dorman and Tech Smart sells aftermarket versions, that are supposed to be improved over the originals versions. NOTE: just replacing the fuse box without; actually fixing the source of the problem, may cause the fuse box, to melt again. Testing and confirming things such as: that there is not resistance in the wiring (alternator charge wire is common), damaged terminal ends, bad grounds and a large amperage draw from failing parts (cooling fans, etc.), should NOT be overlooked.

https://www.newbeetle.org/forums/qu...new-improved-design-solutions-tech-smart.html

If you are having problems with the inside ac/heater blower motor working; you might look at the motor resistor pack and the hvac controller with the fan knob, both which are known to fail.

What could be wrong if the AC and heater fan quit working on a 2000 VW Beetle?

Blown fuse, defective blower motor resistor pack, defective blower motor, or defective fan speed switch.

blower resistor:

https://workshop-manuals.com/volksw...tor_resistor/component_information/locations/

hvac controller:

https://workshop-manuals.com/volksw...and_repair/heating_and_a/c_controls_assembly/

The fan knob internal contacts/lever; can get undone and lose connection inside, cause problems, sometimes melt, in extreme cases, cause a fire.

hvac controller contact lever repair diy:

https://www.newbeetle.org/forums/technical-how/12537-how-fix-c-fan-switch.html

repair video:

https://www.youtube.com/watch?v=lCM-hmN8axU

HELP BLOWER MOTOR NOT Working - TDIClub Forums

This should get you started; let us know, what you find out and we can go from there. Thanks.
 

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Discussion Starter · #4 ·
To Epi - I'm aware of that problem, sadly it is not that. It's the interior driver side fuse box. the base, where the fuse plugs into, is shorting out and melting the box. I appreciate the info!
 
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