72 RS Firewall Bulkhead Wiring Connector

Discussion in 'Electrical Systems' started by Randy S, Oct 9, 2016.

  1. Randy S

    Randy S Veteran Member

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    I'm finally getting around to cleaning up some underhood wiring and can't seem to find a schematic that matches up. This is my '72 RS with an LS1 and there are a handful of wires that I can't identify.

    First pic is a notepad jpg looking at the connector from the engine side. Next few pics are a few wires that have connectors that will hopefully aid identification.

    fw1.jpg fw2.jpg fw3.jpg fw4.jpg fw5.jpg
     
  2. Green hornet

    Green hornet Veteran Member

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    The second photo looks like it shows a black wire. I believe that goes to the transmission for the original TCS system. The third photo shows a blue wire which I believe is for your oil pressure sender. The last photo looks like the connector for your original coolant temp sender and also the TCS system. I'm not sure about the fourth photo. Hope this will help you.
     
  3. grzewnicki

    grzewnicki Veteran Member Lifetime Gold Member

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    Agree with Hornet on his deductions. The wide connector with the blue/brown wires, is that to the alternator? I know the pre-internal regulator alt's used a wide plug like that. Where do those wires end up going, have you traced them out, see if the go to the regulator connector? Funny how we end up with wires that don't match the factory schematics in color. What I found helpful was just using a schematic and bouncing the position of the wire in the bulkhead connector and not worrying about the wire color. Also helps if you lay the harness out like it is installed in the engine bay, wires are only going to reach certain items so that is a giveaway too.
     
  4. Randy S

    Randy S Veteran Member

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    Thanks gents! It's just odd that GM made several hundred thousand of these and I can find a wiring diagram that matches the bulkhead connector.

    I wasn't thinking about the trans, so maybe that's where the black wire/plug goes. I'm with you on the blue wire being for oil pressure. The flat connector is a fit for the general type on an alternator, but I had it in my mind those were white. I bet you're right though; I'll trace the wires back under the dash and see if I can find continuity.
     

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