What is that one wire? - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• What is that one wire? by jhax on 12 Jul, 2014 20:41
• I have my US to CE2 electrical diagram just about squared away. I cant figure out one wire, nowhere to be found in any of the diagrams I have been researching. It is a Light Blue with a black stripe and it goes into a coolant sensor on the transmission side of the head. Any ideas?
  
  Justin
• #1 by ORCoaster on 12 Jul, 2014 20:51
• Isn't that the temperature sender wire?  OR perhaps the glow plug defeat when the engine is warmed up already.
  
  
• #2 by jhax on 12 Jul, 2014 21:57
• Never heard of the glow plug cutoff. The coolant gauge sensor is on the front coolant neck as is the A/C. The engine temp for the glow plugs (blu/wht) is on the neck just below the sensor im referring to along with it's ground wire.
• #3 by theman53 on 13 Jul, 2014 06:07
• They had an a/c cutoff when the car got too hot. I have no clue where it connected or what color it was. Maybe that is the cutoff OR was talking about.
• #4 by Trips_B on 13 Jul, 2014 10:27
• Are we sure its a coolant sensor and not the low oil pressure switch?
• #5 by jhax on 13 Jul, 2014 10:41
• A/C cutoff is a brown green wire on the front of the engine (2 spade connectors one to the compressor and one to the A/C cutoff relay) the oil pressure comes out of the top of the oil filter housing. The one I am referring to is on the transmission side of the engine, coming out of the head above the glow plug temp wire.
• #6 by Trips_B on 13 Jul, 2014 10:47
• looking here http://www.a2resource.com/electrical/CE2.html the only blue black wire in the engine compartment is low oil pressure.
  
  perhaps a picture could help
• #7 by jhax on 13 Jul, 2014 11:02
• I do not have CE2 yet, my car has the US electrical system. Perhaps thats where the confusion was.
• #8 by bajacalal on 13 Jul, 2014 16:01
• Quote from: jhax on 12 Jul, 2014 21:57

  Never heard of the glow plug cutoff. The coolant gauge sensor is on the front coolant neck as is the A/C. The engine temp for the glow plugs (blu/wht) is on the neck just below the sensor im referring to along with it's ground wire.
  

  
  The glow plug relays has the following terminals:
  30 battery +
  87 glow plug feed +
  86 hot (+) in start and run (turns it on)
  85 relay ground (-)
  50 starter solenoid (shuts off plugs if you start the engine prematurely)
  L glow plug LED indicator (grounds the LED)
  T temp sensor (-), this controls the glow plug on-time duration or if they come on at all
  This one is located on the passenger side water neck on the cylinder head, featured one of those "button" type connectors instead of the spade, it is a blue and white wire, at least on the CE1, I think CE2 might be the new style sensor. 
• #9 by jhax on 13 Jul, 2014 16:13
• https://flic.kr/p/ojnRpk
  
  picture is worth a thousand words right? The glow plug wire is on the filler neck below the sensor i have been referring to (red spade connector on the top). Also for those of you using flickr they changed the site so now I am not able to find a specific image url. Is there a work around?
• #10 by ORCoaster on 13 Jul, 2014 16:19
• Blue wire w/red spade connector is on Oil gauge sender.  If you have another on the oil filter area that is another for low pressure light I think.  Brown wire is ground.
  
  I have my oil pressure gauge in that spot on a Tee with the same sender on the end. 
  
  
• #11 by jhax on 13 Jul, 2014 16:42
• Really?! Well I sand corrected then. I figured since it went into the head it was automatically coolant.
  
  Thank You
• #12 by Toby on 13 Jul, 2014 17:01
•  On the Euro system, both the sender on the head and the sender on the oil filter housing are for the oil pressure light, not a gauge. The one in the head is your typical OP switch. The one on the oil filter housing goes ON at about 28 psi. There is a fancy OP light relay that will turn on the light if you have 0 psi and turn it on if you do not have 28 psi or above when you are above 2,000 RPM. On most models you get a solid light with 0 psi and a blinking light with a buzzer if under 28 psi at 2,000+ RPM. If they have a gauge there are 2 senders o0n the oil filter housing.
  
  I think some US systems use this as well.
• #13 by jhax on 13 Jul, 2014 20:47
• cool so head is lo pressure and filter housing is hi pressure then.
• #14 by ORCoaster on 13 Jul, 2014 20:58
• I think you will find that they are both pretty high and the head might be a tad lower when hot and low RPM.