Realize this is not mechanical, but would appreciate some electrical help - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• Realize this is not mechanical, but would appreciate some electrical help by doonboggle on 02 Mar, 2010 19:01
• I need some help with harness wiring.  I have tried to decipher the Bentley schematic drawings, but seem to have ‘missed the boat’ when it comes to understanding how to interpret them.
  
  I have a 1981 rabbit diesel that is ready to have its dash re-installed.  The various plugs of the dash harness were not labeled; my bad; and now want to reconnect everything, and figure out what all the ‘unconnected’ plugs are for.
  
  I have labeled pictures with what I think I figured out, or did in fact figure out ; namely the heater plugs for an a/c heater unit, which is now going to be a non a/c unit. 
  
  I recognize the wiring needs to be converted for the ‘new’ heater. 
  Hopefully someone more knowledgeable can advise.
  
  harness laid out for reference:
  
  
  
  
  What is this plug section for?  Radio or what ? ? ?
  
  
  
  Wiring details, etc.
  
  
  
  I have 2-3 other areas of need, but will post the first question; which is for the wiring and plug above. 
  It is immediately, in the harness, just past the branch for the instrument cluster.
  From its position in the harness, where the radio would be, I ‘think’ it’s for that usage; just need clarification.  No radio was in the vehicle when I bought it.
  
  Thanks.  Will save the other sections to post later.
   
  
  
• #1 by fatmobile on 02 Mar, 2010 19:29
• Most of what you have listed as radio is cigarette lighter. Black/green plugs onto the center, brown to ground and the light for the cig lighter is there too.
   The plug might be defroster,.. only switch I can think of, other than the emergency flashers,.. and you have that.
• #2 by doonboggle on 02 Mar, 2010 20:18
• Another fellow suggested that also;   but ...... in looking at the lighter in the dash that is on my work bench now .... there ain't no corresponding plug recepticle for this (whatever it is); and the lighter itself only has a spade terminal where apparently a 'hot' wire would connect, along with a center post ... later discussed below. 
  
  Also, being a pickup, have never seen one of this vintage with a rear window defroster ...
  but there's lots of things in this old world I have not seen.
  
  But more importantly, beings that this is the ONLY thing in that region of the harness, and that VW would likely have included a radio connection, I sure thought it'd be for a radio.
  
  Here's an image I got from my ETKA with the circle on the rear of what seems to be the cigar lighter.  The rear of mine shows the same single protrusion, which could be where the black plug at the top goes ... and a brown spade connector for the one on the side.
  
  
  
  If only I had a factory radio to check the rear of it....
  
  
  
  
  
  

  Quote from: fatmobile on 02 Mar, 2010 19:29

  Most of what you have listed as radio is cigarette lighter. Black/green plugs onto the center, brown to ground and the light for the cig lighter is there too.
   The plug might be defroster,.. only switch I can think of, other than the emergency flashers,.. and you have that.
  
• #3 by somolovitch3 on 03 Mar, 2010 17:33
• Wht plug with Blk/Yell and Wht/Gn wires is defrost switch, The light bulb is for ashtrey. Odds are that the plug (Bk/Gr) and the brown lead go together...lighter maybe. Its cheaper to build a harness with plugs thaat are never used then to deleate then for the P/U aka 4 dr bunny.
• #4 by doonboggle on 03 Mar, 2010 19:09
• Thanks Somo for confirming my feeling that the brown and black-green is the lighter. 
  Also the lite being for the little box above the lighter.
  
  I still have a question though ... and am not being obstinate by any means.  When you mention the analysis regarding harness and plugs, that's my conundrum .... where is the radio plug? 
  
  This question arises under your premise (which I of course agree with) of it being "cheaper to build a harness with plugs" ... and my feeling that VW's designers 'must have' put in a radio plug in each harness ... rather than the defrost plug ... which I now have had several posters advise.
  
  In other words, why not 'both' plugs; since both would be, in one form or another, important to a certain percentage of customers buying the truck??
  
  And then, accepting it as the defroster plug, if they did not install a radio plug, WHAT THEN did they do for those vehicles that came equipped with a radio??
  
  And lastly, from your well received comments, it seems you may be able to guide me on this point.
  
  What do I need to do to connect a radio to this plug's wires ... not with a matching counterpart plug, but by cutting the plug off and splicing the radio into the pertinent wires ....... and which wires would that be ??
  
  Thanks
  
  
  
  

  Quote from: somolovitch3 on 03 Mar, 2010 17:33

  Wht plug with Blk/Yell and Wht/Gn wires is defrost switch, The light bulb is for ashtrey. Odds are that the plug (Bk/Gr) and the brown lead go together...lighter maybe. Its cheaper to build a harness with plugs thaat are never used then to deleate then for the P/U aka 4 dr bunny.
  
• #5 by fatmobile on 03 Mar, 2010 23:03
• I've seen cig lighters that take that round plug,.. not sure what years.
• #6 by somolovitch3 on 07 Mar, 2010 08:25
• Radio was key opperated, 18 ga Red and 18 ga brown on one plug and wht/brn, grn, 2 brn (4 pin, or two 2 pin) plug(s) for speakers. I don't see anything like that in your pics. You could steal 12+ off the yel/blk wire/connection as well as ground (brwn lead), but since that comes from load reduction relay...should not be a problem.