Hey everyone,
Posted this yesterday to Pelican, but it seems to have gotten lost in the fascinating 'Por-sha' debate. Answers here aren't critical to me getting my car put back together, but seem worthwhile from a documentation standpoint. The various years' electrical systems aren't all that easy to find clear information on. So, in hopes that this helps, please help me figure out all the connections on this engine harness.
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As I continue reassembling my car (1970 carbureted T), I've been slogging through getting the electrical system back together. My car came to me with no rear electrical panel or engine harness, so I've purchased used components, none of which are a perfect match for my 1970. The engine harness in particular has a number of what appear to be superfluous (later) components. While I've identified most everything on here, I'd like to confirm a few identities before I begin modifying things (more on this below).
Below is a labelled picture of the harness. See question marks for my uncertainties. Let me mention first that I've perused all available wiring diagrams, and this seems to be from the 71-73 period, for which nothing is easily availble online).
1. The biggest mystery to me now is a small cluster of yellow wires (three yellow wires into two spade connectors, labelled 'O2 sensor?' in the photo) branching off near the starter. I have not been able to find continuity with anything else in the harness. Possibly some emissions sensors?
2. Next to those there's a plug with two minute male spades, and a yellow and red-black wire going into them. This has continuity with the two spaded connectors in the boot (same color wires) near the 14-pin connector. I'm thinking this is a thermo-time switch (colors match) but in all diagrams I've looked at these wires come back through the 14-pin instead of being internal to the harness. I've also read that that type connector is used for warm-up regulators - so maybe a CIS option?
3. There are two voltage regulator connections, (one at the very base, bottom of the harness, one branching nearly opposite the alternator cluster.) I suppose these are alternatives depending on whether an internal or external voltage reg is used. Can anyone confirm? Interesting that the D+ and D- (blue and ground) are on the same spade on the internal connector. (These are also doubled up coming through the normally ground (#12) pin on the 14-pin connector.)
4. Red-white wire next to internal voltage reg plug, single spade connector: Cold-start solenoid on carbs? (On 70 diagram this color matches but is fed from a 'microswitch' whose wire then goes back through the 14-pin.
That's all the indentity questions. Last, I'm planning to go to MSD, and intend to remove the CDI plug, its power lead (2 pin connector close to CDI plug), and the coax/shielded coil and distributor wires (removing all intact by untaping the harness), replacing with new/simple wiring specific to the MSD application, which need not be coax. These coax wires were already poorly modified and would at least need replacement. Any comment?
Thanks,
Mike
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