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'85 240 wiring harness destinations?

it's painfully clear to me that the infamous harness has self-destructed. i've decided to re-route the wires individually instead of replacing the harness threading through the manifold, etc.

can anyone provide "red wire to alternator; black wire to oil pressure sender; etc"? or tell me where to find it. my haynes manual doesn't quite get me there.








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    '85 240 wiring harness destinations?

    I'm thinking of the same method on my son's '86 (225 miles away). I'd start at the 8-pin FW plug (FW side to eliminate plug connection corrosion, etc.).

    Not sure how many wires yet, but know of these ones from memory:

    Red - Alternator D+
    Black - Oil pressure switch
    Yellow - Temp gauge sensor

    Another Black - Engine Coolant Temp (ECT) sensor LH FI (1 of 2 ECT wires)
    Blue - also ECT, the other wire

    Blue/Yellow - Starter solenoid #50
    Green - AC (not sure of destination, Accumulator or Compressor?)

    That's 7 of 8--don't know if there is an 8th on '85 & '86.

    I have them mapped by plug # for older cars, but not LH
    --
    Bruce Young
    '93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.








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      '85 240 wiring harness destinations - the four wires.....

      Previous post is more than you need.

      Red - Alternator D+
      Black - Oil pressure switch
      Yellow - Temp gauge sensor
      Blue/Yellow - Starter solenoid #50


      Do the "destination" ends first. Try to get same-color wire, 16gauge. Except for oil pressure sensor, the wires use female spade lug connectors.

      Do the red and black first. Route all the way to the firewall connector, leave some slack.

      The other two, yellow and blue/yellow, run under the intake manifold. Put some protection on them.

      On the starter it's important that (1) the battery is disconnected, and (2) remove ONLY after noting which terminal is goes to. There are two spades down there.

      After you get the four ends up near the gray connector, then you can work that end, just like other posts said. Be sure to note what wire goes into what pigeon-hole. The metal clip can come off the firewall, and the connector has little hinges to allow opening up the side so as to remove the weird little connectors in there.

      It's sort of a long many-pieces job, but a good DIY when you compare to the non-DIY costs. If other wires in the main harness are going bad, this fix won't cure them. However, this fix will prevent many many problems,

      Good Luck,

      Bob

      :>)








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        '85 240 wiring harness destinations - the four wires.....

        Previous post is more than you need.

        Why do you say that, Bob? Surely the ECT wires are subject to the same insulation problems aren't they? I thought the idea was to replace all the wires in that FW plug.

        --
        Bruce Young
        '93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.








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          '85 240 wiring harness destinations - the four wires.....

          Hi Bruce -

          The ECT wires that I have seen, and you likely have seen more than I, seemed OK, just covered with bits of insulation from the same-harness wires.

          It also occurred to me that the guy asking for help was focussed on the gray connector wires, rather than the whole thing. Of course it is best to replace the entire harness, but given the restraints of time and money, doing the four will often help a lot. Please take no offense, none was intended.

          BTW - I read your posts and am always impressed with yoUr knowledge. Thanks for helping so many of us readers, self included.

          Regards,

          Bob

          :>)








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            '85 240 wiring harness destinations - the four wires.....

            Hi Bob,

            No offense taken at all. I was just surprised, curious, and probably mistaken — because in my rather limited harness experience (mainly making one up for a '83 turbo), the Red and Blue ECT wires did come thru the gray firewall connector (of which there were two).

            The Bentley diagram for the '86 shows a "connector" symbol in the Blue ECT wire, so I assumed it was the FW connector. (Don't know where I got the notion for the Black one though. AFAIK, it grounds right on the intake manifold?)

            Another assumption was that the wires I listed (those with engine destinations) all come thru the FW connector, for convenience when changing engines — and that they'd all be "biodegradable" candidates for replacement. (i.e., if the temp gauge wire, why not the ECT wire too?)

            Hope my ass-umptions didn't steer too many people wrong.
            --
            Bruce Young
            '93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.








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    '85 240 wiring harness destinations?

    Both of those items connect at the grey pillow block connector on the firewall( right above the intake manifold or there abouts) along with the dash temp sender and the wire for the starter solenoid, if I remember correctly. They (alternator f+ and oil presss sender)can be re-routed along the passenger side wheel well. I used the plastic spiral wrap/harness maker to prevent future chafing, crimped then soldered new connectors and finally used heatshrink tubing to seal. A good DMM will help locate, and confirm success. Good luck!







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