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Electrical Starting Issue - No power to started

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Old 07-16-2017, 06:10 PM   #1
lsintampa
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Default Electrical Starting Issue - No power to started

1975 Coupe A/C, automatic.

Problem: Starter not getting any power. When I turn key to start, nothing happens - except the BRAKE light in the instrument panel lights up.

Old seat belts long ago deleted by some PO. So the seat belt warning wiring is most likely tied / cut off.

A/C is being replaced so the old harness, etc. long gone. I don't think that has much to do with my issue.

Worth noting that the car did RUN and start fine before I tore into it.

It appears that someone removed / bypassed or rigged the neutral safety connections or something in the starter circuit. I have to admit that I never tried to start the car in any position other that park or neutral, so I can't say what they did.

Z28 motor in this car - if it matters.

I have AIM (not very helpful for this issue) and some wire diagram, which also isn't very helpful.

There seems to be a purple white wire that was cut (along with many other wires that were cut and tied off), but the purple white wire that was cut was spliced to some relay that has a jumper in it for some reason. This relay doesn't go anywhere. Wires coming out are just cut.

Anyway, I have no clue what someone was trying to do and at this point I don't know what I need to do to get the starter to engage again.

BTW - backup lights do work, so some of the shifter wiring seems correct.

Pictures attached:

1) The relay that the cut purple white wires are tied in. Picture is poor, but there is a jumper between the outbound wires (that go nowhere)... the jumper seems to have a resistor in it. FWIW - wires out are red and orange.

2) The purple white wire that was cut then spliced into the relay noted above. Not sure if orientation is important as to how they go to the relay or not??? Makes little sense to me as to what this relay is for - given it is jumped and really goes nowhere.... but I'm not electrical minded.

3) This is the purple and purple white wires that comes out the back of the cut wire connector. As you can see it goes to air. So purple and purple white are switched at the connector. The PW wire IN from the harness is what was cut.

4) The purple / yellow also comes out of that connector with the purple / purple white. I don't recall if this connector was attached or just hanging in air. I believe it was just hanging and not connected.

5) Pink wire coming off the selector connection was cut and spliced to the pink coming out of the pink / green connection.

6) The shifter connector... notice the missing wire on the bottom. That's how it was folks.

BTY that purple white coming out of the top of the selector connection (last photo) seems to have been cut. It ties directly into a thick black wire that runs out under the dash - out to the engine bay via the steering column opening - to a fused connection to the A/C wire harness (engine side) that I've removed. So the fact that it "was" purple white at some point, I really don't know where it went originally or why it was used as a ground for the A/C engine harness.

Anyway, I'm really stuck with this mess and can't seem to find any help from the resources I have and those that I've tried to find.

ANY insights would be very helpful.

Thanks,

Len
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Old 07-16-2017, 06:37 PM   #2
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Looks like one wire is taken off the neutral safety switch at the shifter. also the purple with white stripe is cut. To test the start circuit, jump the purple to the purple with white stripe.
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Old 07-16-2017, 06:54 PM   #3
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Quote:
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Looks like one wire is taken off the neutral safety switch at the shifter. also the purple with white stripe is cut. To test the start circuit, jump the purple to the purple with white stripe.
So just jump the first two wires on the neutral safety switch?
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Old 07-16-2017, 07:01 PM   #4
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In the 1st pic with the large purple and purple/white wires, if those two are jumped together, it bypasses the neutral safety switch.
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Old 07-16-2017, 07:03 PM   #5
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Sorry, 2nd pic
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Old 07-16-2017, 07:38 PM   #6
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Sorry, 2nd pic

Will give it a try tomorrow.....
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Old 07-17-2017, 03:29 PM   #7
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Quote:
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Looks like one wire is taken off the neutral safety switch at the shifter. also the purple with white stripe is cut. To test the start circuit, jump the purple to the purple with white stripe.
Took some digging.... had to trace wires to the engine bay... then unwrap a bunch of sticky electrical tape.... the patched purple/white wire on the neutral switch went to the solenoid but had come apart midway. Once I got the solenoid wire patched and then jumped purple / purple - white - I was able to crank motor.

Testing continuity on the neutral switch - when in park the purple / purple white would be connected, allowing for the engine to crank. But in neutral, there is no continuity. I have no issue with this, but shouldn't the engine still crank in neutral?

What is a good electrical tape to use to harness wires together? I'm now a fan of twist and tie / tape method, but I would like to harness some wires together and the stupid black plastic tapes always seem to come apart / get messy in time.

AND THANKS FOR THE HELP!
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Old 07-17-2017, 04:22 PM   #8
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The best way to splice is a mechanical crimp= For that 10ga wire, I'd go with the yellow butt splice connectors and then wrap with a combination of Skotch(sp?) 33+ covered by a layer or two of self vulcanizing silicone tape. The silicone tape pretty much welds itself together and will keep moisture out of the splice. I got a roll at Lowe's for $14 or so.
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Old 07-17-2017, 10:27 PM   #9
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Yes it should have continuity in neutral also, sounds like your ns switch is getting bad, might be the right time to replace it.
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Old 07-18-2017, 10:37 AM   #10
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So the green and pink are the back up lights... they work.

What is the pink-white wire for?
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Old 07-18-2017, 11:19 AM   #11
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Quote:
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What is the pink-white wire for?
If you shift out of PARK and the seat belts are not buckled up the pink-white sends 12 volts to the seat belt light and buzzer.
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Old 07-18-2017, 12:13 PM   #12
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If you shift out of PARK and the seat belts are not buckled up the pink-white sends 12 volts to the seat belt light and buzzer.
Seat belt warning long gone from some PO. It would be nice however to test that circuit and add it back (IF I can find the correct belts)... AND a circuit diagram.

Thanks!
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