Another Fuse 14 / CCM Thread - Advanced Help Needed!

Lex4TDI4Life

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Joined
Jun 22, 2006
Location
NorCal
TDI
2001 Golf-Ute TDI GLS 5spd Manual
Howdy!

In the course of cutting my beloved Golf up for a Smyth Ute Conversion (build thread here: http://forums.tdiclub.com/showthread.php?t=503316) I have found a way to keep blowing Fuse 14 (and only fuse 14), which pretty much shuts down all the central locking, windows, interior lights, etc. because it feeds the Comfort Control Module ("CCM").

I have gone through the harness going out to what used to be the hatch and patched some spots where wiring insulation has broken. I also covered in electrical tape any connections I will not be using (e.g. hatch release actuator connector). I have removed my headliner for re-lining and have similarly checked the interior light connections for breaks in the insulation and taped off any exposed connector ends. Fuse 14 keeps blowing. Grrrrrr....

To aid my diagnosis, I removed one of the two connectors at a time from the CCM and placed a fuse back in. Only connecting the blue, 23-pin connector causes it to blow, so I can narrow down my leads for a short in the system. This also leads me to believe that the CCM itself is ok.

I really want to avoid tearing apart the harness any further until I know which wire is shorting. I have a Bentley with wiring diagrams and have invested in an electrical diagnostic tool in hopes of hunting down the short causing this. Sadly, I am an electrical dumb dumb and I have questions that I would greatly appreciate help with:
  • Would merely having items unplugged (lights, hatch release motor) trigger a short?
  • If the other connector going into the CCM does not trigger a short, could it still be a bad CCM?
  • There are a few fuses that feed to/from that 23-pin connector: Fuse 14, Fuse S111 and S144, Fuse 37. None of these other fuses appear to be blowing. Are there components that specifically feed Fuse 14? This wasn't obvious in the wiring diagrams.
  • Would I be able to trace the short by placing the probe into the individual contacts in the 23-pin connector if there is another switch or module in between? I am thinking of the interior lights. There is an interior light module that feeds into the 23-pin connector, but the individual lights sit on the other side of the module. If the short is between the light and the interior light module, will it show at the 23-pin connector into the CCM?

Again, electrical is one of my many Achilles heels (oddly, I have more than two), so any guidance would be MOST appreciated.

TIA,
-Lex
 

JB05

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Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
Has your sun roof drains ever clogged up; causing water to flow out the left kick panel by the hood release? I would look behind the kick panel where there are two or three connectors that are vulnerable to moisture damage.
 

Lex4TDI4Life

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Joined
Jun 22, 2006
Location
NorCal
TDI
2001 Golf-Ute TDI GLS 5spd Manual
Has your sun roof drains ever clogged up; causing water to flow out the left kick panel by the hood release? I would look behind the kick panel where there are two or three connectors that are vulnerable to moisture damage.
No sunroof, thank goodness! I forgot that there are hatch connectors running down the passenger side of the car that I haven't checked. I need to remove my loosely-fitted body panel to get to it, so I will keep my fingers crossed that it is the culprit.
 

KrashDH

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Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
I have gone through the harness going out to what used to be the hatch and patched some spots where wiring insulation has broken. I also covered in electrical tape any connections I will not be using (e.g. hatch release actuator connector).
If you have fixed the broken wires in the boots with the same wires in the harness, it's not an if, but when they will fail again, even with quality connectors. The wires in there are just too brittle and stiff. I applied a temporary fix twice before I did the permanent budget fix (replacing that run of wires through the boot with extremely flexible silicone wiring).

The first time the wires broke everything went, including the central locking system, lights, defroster, latch mech, etc. Second time I knew they were going, defroster stopped working again and defrost button was orange/orange (off/on) instead of red/orange (off/on).

Here's my tech write-up on the how to if this is your issue:

http://forums.tdiclub.com/showthread.php?t=504001
 

Lex4TDI4Life

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Joined
Jun 22, 2006
Location
NorCal
TDI
2001 Golf-Ute TDI GLS 5spd Manual
If you have fixed the broken wires in the boots with the same wires in the harness, it's not an if, but when they will fail again, even with quality connectors. The wires in there are just too brittle and stiff. I applied a temporary fix twice before I did the permanent budget fix (replacing that run of wires through the boot with extremely flexible silicone wiring).
The first time the wires broke everything went, including the central locking system, lights, defroster, latch mech, etc. Second time I knew they were going, defroster stopped working again and defrost button was orange/orange (off/on) instead of red/orange (off/on).
Here's my tech write-up on the how to if this is your issue:
http://forums.tdiclub.com/showthread.php?t=504001
Yup. I saw that one - very good write up! I am not saying I am immune to further failure, but because I have chopped off my roof and hatch, the only wires of any use going to the back of the car are the brake, tail, and reverse lights - there is no longer a hatch release, rear wiper, defogger. Because there is no hatch, there will be no repeated movement to stress any wires. If it looks like I really cannot track down the short, I may very well cut and terminate the extraneous wires.
 

wonneber

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Oct 12, 2011
Location
Monroe, NY, USA
TDI
2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
As far an I can tell fuse 14 only feeds the CCM
If the fuse blows instantly then the CCM could be bad or something the CCM feeds is blowing it.

Sorry, there's no easy way I know of to check this.
I use a clamp on amp meter to check if how much power a wire has running through it.
You would have to open the harness and check each wire one at a time.

I don't have a power probe (not just a test light) but I think they have the ability to limit how much power is going to a circuit.
 

KrashDH

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Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Yup. I saw that one - very good write up! I am not saying I am immune to further failure, but because I have chopped off my roof and hatch, the only wires of any use going to the back of the car are the brake, tail, and reverse lights - there is no longer a hatch release, rear wiper, defogger. Because there is no hatch, there will be no repeated movement to stress any wires. If it looks like I really cannot track down the short, I may very well cut and terminate the extraneous wires.
Ahh I see, cool. Thanks for the clarification! Interested to see this rig!
 

Lex4TDI4Life

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Joined
Jun 22, 2006
Location
NorCal
TDI
2001 Golf-Ute TDI GLS 5spd Manual
Problem (mostly) solved!

Using a circuit tester (https://www.amazon.com/Kzyee-KM10-Automotive-Electrical-Multimeter/dp/B071LHLSBB), I tested each pin in the blue, 23-pin connector feeding into the right side of the CCM. Position 18 was the only one shorting. This is a blue and red wire that feeds to the interior lights. Remember, the interior lights are not currently connected because (1) I have no rear interior lights anymore; and (2) I have pulled the headliner for eventual reupholstering.

Just to make sure I found the right circuit, I tested the red/blue lead at each of the interior light connectors - each one showed a short. I am not sure if this means that the interior light module is bad or whether a short in one of the wires results in all of them showing a short. I realllllly hope it's the latter, because the interior light connector is behind the instrument panel and tearing apart the dash is not on my agenda. I peeled back the conduit on each of the wire bundles leading to an interior light and inspected for shorts - nothing.

My short-term fix is admittedly ghetto - I cut the red/blue wire leading into the connector and terminated both cut ends. My pin removal tool did not want to comply with popping the pin out.

In the spring when I have more time and better weather, I will track down the short and button everything back up with a new headliner. Thanks everyone for listening to me think this out!
 
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wonneber

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Oct 12, 2011
Location
Monroe, NY, USA
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2014 Jetta Sportwagon,2003 Jetta 261K Sold but not forgotten
I am not sure if this means that the interior light module is bad or whether a short in one of the wires results in all of them showing a short.
It could be either.
You could pull the module to see what happens. (when it warmer)
If that wire feeds 6 lights (or so) then the short could be anywhere the wire runs to them.
 
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