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Very unusual electrical issue
#1
Hey guys/gals, it's good to be back on the site. I need to update my project pics but I am in a predicament I've never dealt with before. I was trying to start the new engine in the '72 when I realized all of my connections are just receiving power at all times. I cannot find a switchable power source from ignition. Any ideas? It's a 429 engine with 302 electrical harnesses from the old motor. I haven't checked the fuses yet either.
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#2
Battery power enters the main harness and routes to: ignition switch, fuse box, headlight switch and dash (if tach-configured). Sounds like your ignition switch is bad or out of adjustment.

Let me check your shorts!
http://midlifeharness.com

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[Image: oldfart.png]
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#3
I'd have to agree except that I had power to lights brakes and interior when i first got the car gutted. I haven't changed any wiring and now I'm not getting power to anything. Fuses look ok as well. Thanks for the clarification, I guess I'm going to have to trace back wires to the ignition switch and ultimately find out why I'm getting readings of voltage and nothing's turning on.
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#4
did you take anything apart by the voltage regulator.

its been a long time but there is a black/orange stripe thick wire by the battery that is suppose to be isolated from ground. its suppose to go on the wire block above the battery that isolates it from body ground. sometimes people think it is suppose to be grounded and they bolt it to the engine bay aprons and cause a short.

i know that the engine harness comes around from the left hand side and gives you the connections for the regulator and starter solenoid this includes another black and orange stripe wire that is suppose to connect with the regulator harness wire and be isolated from body ground both wires have a large electrical grommet for the connection. I know if that connector isn't right then it won't power the dash wires.

also check the starter solenoid is hooked up correctly you can flip the 2 middle boot wires and cause a problem like you describe.

do you have the engine ground wire attached as well?
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#5
it sounds to me like you blew the fusible link.

[Image: 1_01_07_15_8_53_18.png]

"I love my Hookers!" and "Get some Strange" probably have a different connotation to non automotive enthusiasts!
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#6
Thanks for all the help 72HCode. If by engine ground wire you mean the ground from the battery then yes I have it bolted to the cylinder head. To be honest the wires are so old that I can't make out most of the colors. I do know the wires are fine because they worked before I repainted the engine bay. Connected the neutral safety switch and shifter wire and still nothing. I deleted one fusible link but not the other. I could try and delete all of them. Here's a pic of what I currently have setup. The second pic is that other harness that I know goes to the coil and oil pressure sender but not sure on the others.

   

Here's the second pic I forgot

   

As a side note...to make the pictures more clear turn screen sideways lol. Anyways, I don't have a battery tray yet so that's the yellow thing hanging and the alternator is at the bottom left of the screen. Using the old alt just to plug stuff up and test connections. Hope that helps
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#7
the first picture i tried to compare to my car.

i think you have that black wire with the green connector on the left side of the starter solenoid connected incorrectly.


here have a look
[Image: 100_2918_zpsd5a70e2c.jpg]
[Image: 100_2917_zps01948c4b.jpg]
[Image: 100_2920_zps9e3735be.jpg]

the second photo, you have the; oil sender, the carb idle up solenoid, the A/C compressor magnetic clutch connector, coil, and coolant temp sender.

if you ditched the stock carb then the idle up solenoid can be used as a electric choke connection. it is powered 12v switched when the key is set to start and run and shutdown when the ignition is off or ACC mode.
the original purpose was on A/C cars there was more drag and it required a very high idle however the cars would diesel after shutdown when hot, so ford made the idle up solenoid that bumped up idle high to compensate and then on shutdown the solenoid allowed the carb to completely drop idle rpms to prevent run on after shutdown. so the solenoid was on all the time except when the engine was shutdown, perfect for an electric choke.


if you have some 100% isopropyl alcohol put some on a rag and you can clean up the wires and connectors so you can read the colors easier.
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#8
72HCode, +1 on the clean engine bay! Ok so I see I'm missing that black connection piece attached to the apron next to the starter solenoid. Is that a ground? Also I do see you don't have the wire going to the left side of the solenoid that I have. I'll take that off. That is from the alternator so I think that one goes to the black connection piece on the apron which I'm assuming is a ground.

Also, thanks for describing that last picture picture. Theoretically, the engine should still fire and I should still get power to all accessories if that whole harness is unplugged because that's just the engine sensors correct? If so I can worry about that last.

I do have the stock carb from a 71 Thunderbird (where the motor came from) so I'll use that carb solenoid as such and I'll also splice into it for my HEI distributor.

Thanks again 72H!
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#9
pics are from a couple years ago another member asked about wiring and i remembered i had photos. I rebuilt my entire front end back in 2007 try to keep the bay clean but its a driver Smile

the junction block on the apron is a ground isolator, basically its a piece of plastic that bolts to the apron and has a bolt molded into it so you can hook up that black and orange stripe wire to it. from the alternator harness that large black wire with the large eyelet goes to the ground isolator junction block, then from the engine harness is a similar black wire and they go together on that junction block.. you can tie both wires together and then wrap it in electrical tape to prevent a short, quick way to try and see if it solves the problem you have also. I remember way back somebody had wired that black-orange stripe wire wrong on my car and i had no power to my dash at all.

the only thing is the green and red wire is your coil wire so you need that, everything else is sensors and A/C.

it won't hurt to hook up the sensors and see what is working on the dashboard gauges. be nice if you get a oil and coolant signal on the dash.

well all this may not solve the issue but lead you closer to finding the source of the problem.

I rebuilt my engine harness i had a lot of broken wires and broken connectors on my car you could still have a broken ground or a wire somewhere.



afeng79;196311 Wrote:72HCode, +1 on the clean engine bay! Ok so I see I'm missing that black connection piece attached to the apron next to the starter solenoid. Is that a ground? Also I do see you don't have the wire going to the left side of the solenoid that I have. I'll take that off. That is from the alternator so I think that one goes to the black connection piece on the apron which I'm assuming is a ground.

Also, thanks for describing that last picture picture. Theoretically, the engine should still fire and I should still get power to all accessories if that whole harness is unplugged because that's just the engine sensors correct? If so I can worry about that last.

I do have the stock carb from a 71 Thunderbird (where the motor came from) so I'll use that carb solenoid as such and I'll also splice into it for my HEI distributor.

Thanks again 72H!
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#10
72HCODE;196267 Wrote:the first picture i tried to compare to my car.

i think you have that black wire with the green connector on the left side of the starter solenoid connected incorrectly.


here have a look
[Image: 100_2918_zpsd5a70e2c.jpg]
[Image: 100_2917_zps01948c4b.jpg]
[Image: 100_2920_zps9e3735be.jpg]

the second photo, you have the; oil sender, the carb idle up solenoid, the A/C compressor magnetic clutch connector, coil, and coolant temp sender.

if you ditched the stock carb then the idle up solenoid can be used as a electric choke connection. it is powered 12v switched when the key is set to start and run and shutdown when the ignition is off or ACC mode.
the original purpose was on A/C cars there was more drag and it required a very high idle however the cars would diesel after shutdown when hot, so ford made the idle up solenoid that bumped up idle high to compensate and then on shutdown the solenoid allowed the carb to completely drop idle rpms to prevent run on after shutdown. so the solenoid was on all the time except when the engine was shutdown, perfect for an electric choke.


if you have some 100% isopropyl alcohol put some on a rag and you can clean up the wires and connectors so you can read the colors easier.

72 H code I don't want to highjack the post. I was wonder where you got the bracket that goes from the battery hold down to the fender sidewall. Mine is missing and I need the bolt and the bracket.

Thanks John J
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