Technical Single turbo top mount guys keeping a/c!

[DCook]

So, for a while now ive been chasing a intermittent a/c issue. Then it finally quit all together. After a replacement compressor and expansion valve that still didnt fix it. And a few posts and discussion elsewhere, finally got down to the bottom of it.

I kept getting codes for rear potentiometer 9c69, and all the threads I've come across are pinched wires for the rear heat/ac stratification selector. Well, after literally pulling all tesa tape off and tracing wires and finding nothing, and then reading up more on inpa values and seeing the high pressure side at 0 i checked the sensor/wires and found they were beyond melted. I also want to add here, the front wheel speed sensor wire and coolant level wires were ran here too. And the speed sensor wire was screwed too. And, i got dsc and steering angle codes. All junction box related.

I drive the ever living hell out of my car, soon to be 4 motors, shes seen a lot of 30+psi pulls and a metric ton of heat in that area. So im not surprised by this. Just sucks took forever to find! Also, i do run a turbo blanket, just off for the pictures.

So, to all the top mount single turbo guys, check your wiring, and if you begin to have issues with your dsc/abs/ac, check your wires by the exhaust housing! Also wanted to throw it here in the n54 section, as its best here i feel. If not feel free to move! Maybe someday if someone else runs into this issue like me, it'll come up searching!

 

[twinturbos]

That was like... the first shit that I relocated when I did the top mount....... Did you think it wouldn't melt ?

 

[DCook]

That was like... the first shit that I relocated when I did the top mount....... Did you think it wouldn't melt ?

Didnt even think of it to be honest. I was assuming it was just for the coolant level sensor that gets moved and a washer fluid sensor related and wrote it off....wasnt ever really mentioned or i didnt read people relocated the speed sensor and pressure sensor wires. Stuff happens ya know?

 

[derekgates]

Thanks for the post, good to spread the word on these kinds of things. I am not single turbo but I would probably get tripped up on this as well!

 

[twinturbos]

Didnt even think of it to be honest. I was assuming it was just for the coolant level sensor that gets moved and a washer fluid sensor related and wrote it off....wasnt ever really mentioned or i didnt read people relocated the speed sensor and pressure sensor wires. Stuff happens ya know?

Didn't mean to sound like an ass, sorry.
It can be relocated to go under wheel housing. Cables were long enough but now that you have to re-do it you can probably do it a better way.

 

[DCook]

Didn't mean to sound like an ass, sorry.

Youre good man!! I give you credit for thinking ahead. I did not, and you see the problem it caused!

 

[TWilly]

yikes i dont remember if i relocated my wiring and i also have an ABS light. also wouldnt know about the AC because the heat from the downpipe melted the secstion of hose for that AC line that runs down there... anyone else have that issue? i am coated and heat wrapped and i used that damn reflective tape.

 

[twinturbos]

yikes i dont remember if i relocated my wiring and i also have an ABS light. also wouldnt know about the AC because the heat from the downpipe melted the secstion of hose for that AC line that runs down there... anyone else have that issue? i am coated and heat wrapped and i used that damn reflective tape.

Reflective tape won't be enough. It will reflect the heat but the heat can't go anywhere since its stuck between the turbo blanket and your shock tower. Temperature will rise and it will melt.

 

[TWilly]

so whats the alternative? are people running the AC line else where?

 

[DCook]

yikes i dont remember if i relocated my wiring and i also have an ABS light. also wouldnt know about the AC because the heat from the downpipe melted the secstion of hose for that AC line that runs down there... anyone else have that issue? i am coated and heat wrapped and i used that damn reflective tape.

I havent ran into this....yet i guess i shall say. Only time will tell! I guess when i switch to motor #4 i will figure it out then now that you mention it, and wrap/tape/both. Considering its the high side, hopefully it doesnt "explode" and burst into flames from the refrigerant....

But yeah, check your wiring. Mine showed right rear wheel speed sensor..i dont know if it was a generic fault or what. But worth looking into as it can cause other areas to fudge! And especially cruise control!

 

[twinturbos]

so whats the alternative? are people running the AC line else where?

The A/C line has been fine for me. The wiring going to that sensor or whatever it is however needs to be relocated.

 

[TWilly]

@twinturbos what kit you have? I use the VM/ASF kit which has the larger downpipe I wonder if that plays into effect

 

[twinturbos]

@twinturbos what kit you have? I use the VM/ASF kit which has the larger downpipe I wonder if that plays into effect

Docrace. If you heat wrap it properly with good quality stuff should be good to go.

 

[Payam@BMS]

yikes i dont remember if i relocated my wiring and i also have an ABS light. also wouldnt know about the AC because the heat from the downpipe melted the secstion of hose for that AC line that runs down there... anyone else have that issue? i am coated and heat wrapped and i used that damn reflective tape.

You can relocate the wiring under the fender liner and stuff.

The rubber part of the AC line will touch your 3.5" DP. You'll need to move the AC line up. Take it off the bracket and you'll have to bend the ac line up and over a little. Then you'll be fine. Make sure the DP is wrapped and you have a turbo blanket on.

 

[TWilly]

thanks payam! wish i would of known that before it rubbed through but oh well i guess... you have any pics of the ac line modified?

 

[Payam@BMS]

I'll try and snap some off my car, but I don't have the top mount anymore so it might not be as clear.