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Electrical - Where do I even start?

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Old Oct 5, 2014 | 02:58 PM
  #1  
oft's Avatar
oft
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Electrical - Where do I even start?

So my 76 has been sitting forever and now I'm trying to get it going again. Electrically this thing is a nightmare. I had a guy work on it while I was in Afghanistan - he got all the lights to work. But the blinkers come on sometimes or not at all. Brake lights will work when the lights are on but one wont when they're off - sometimes. 4 ways work sometimes but sometimes one of the lights wont flash. Instrument lights don't work at all.

I am not sure where to start here. For instance, if I look at a brake light that doesn't work, in the course of looking at it, it'll start to work. Then it wont.

I don't know where to start here - thinking of taking it to a shop at this point.
 
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Old Oct 5, 2014 | 03:34 PM
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weez440
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From: NW MINNESOTA
my advice is to first bang your head against the wall. then just take it one thing at a time. trace wires and get a good wire tester. and be patient. having someone else work on the truck he might have hooked up or crossed wires somewhere. make sure to clean grounds good. and also get a wire schematic so it makes it easier to just look at the color of the wire and determine what it is for.

edit: https://www.ford-trucks.com/forums/1...then-some.html post number 10 has the wire schematics on it.
 
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Old Oct 5, 2014 | 03:47 PM
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HIO Silver
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From: NorCal
Take a deep breath....

The electrical system is made up of subsystems (circuits). Identify which circuits are malfunctioning. Study the wiring diagrams and identify the potential culprits. Sometimes they point to a common component.

Patience, a multimeter, and deductive reasoning is what ya need to employ. The typical problem usually involve the turn signal switch and headlight switch.... of course, hacked wiring my previous owners is also a possibility.

With the truck sitting so long, first look for corroded bulb contacts and bulbs that aren't seated correctly. Clean them, apply dielectric grease, and move on to the next upstream electrical component like a connector that is not fully seated. Verify that the component is grounded... it's amazing how many times I have found a grounding terminal with a loose screw.

Here are some simplified wiring diagrams for reference:

74-78 Wiring Diagram Pt1
74-78 Wiring Diagram Pt2
 
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Old Oct 5, 2014 | 05:28 PM
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77&79F250
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https://www.ford-trucks.com/forums/1...se-read-2.html

Post #16 and 17 will get you off to a great start.
 
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Old Oct 5, 2014 | 07:35 PM
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TheStuffz
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From: Estevan, Saskatchewan
if its all a hack job and you're tired of banging your head off the wall, maybe look into a painless wiring harness. painless is the company name.
 
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