79 140hp 181 cid wiring harness

Jpcaravelle

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Jan 12, 2020
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Hey guys long time lurker first time poster. Trying to find a wiring diagram for. 79 140hp 181 cid. I replaced the fuel pump, its now getting fuel to the carb. But I’m still not getting fire. The guy who installed the motor didn’t quite know what he was doing. He had the firing order wrong, but I suspect he has also just put the distributor back in wrong and not at TDC because it is turned about 90 degrees from being parallel with the cylinders. But I’m not even sure the engine wire harness is hooked into the right places. I noticed a black wire just hanging from the harness behind the motor, can see two wires hooked up to one spot on the shift switch . Once I figure out where everything properly hooks to I’ll try to figure out how to check the plug wires points and the coil. Thanks for any help!
 

Scott Danforth

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Service your points

Links to manuals (that have schematics) in the stickies
 

Jpcaravelle

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Yes after I find out how to hook the harness up properly, I will adjust distributor, service points and new plug wires. But right now I cannot find anything on the harness.
 

Bt Doctur

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Stand by,
Click the picture to enlarge it
 
Last edited:

achris

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What colour wire is coming out of the back of the alternator (the big output wire)? It will be either Orange or red/white. And do you have a voltmeter or an ammeter on the instrument panel?

With that information, I can get you the right drawing.

Chris...........
 

Jpcaravelle

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There is an orange and black, but then there are 2 other wires that come off the alternator going into the harness. One is red and the other is purple or purple/white and yes there is a amp meter on the panel.
 

achris

More fish than mountain goat
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There is an orange and black, but then there are 2 other wires that come off the alternator going into the harness. One is red and the other is purple or purple/white and yes there is a amp meter on the panel.

Something's not right. The engine harness colours are for a later engine, that uses BIA colours and a voltmeter not an ammeter... You can't mix instrument panels without significant wiring changes...

Chris....
 

Jpcaravelle

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Alright I am going to try to get some pictures on here today. The rain has let up today, so maybe I can get out and mess with it.
 

Scott Danforth

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assuming points have been serviced and the dizzy is stabbed correctly, to get the motor to run, simply provide 12 volts to the coil + and turn it over.

normally the coil + is supplied via a ballast wire or resistor in a points application which drops the voltage down to 6 volts. There is a wire off the starter "i" terminal which provides a full 12 volts during cranking (you never want to run points at full voltage for long)

back of the block is normally the system grounding point (where all the negative wires meet the negative battery cable)

wiring colors are standard (BIA and ABYC use the SAE color scheme)
grey wire is tach
purple wire is ignition (12 volt after key switch)
purple wire with yellow stripe is voltage to coil during cranking
yellow wire with red stripe is crank signal
tan wire is temperature
light blue wire is oil pressure
black is system ground
red is battery cable to starter
Orange is charge from alternator to starter
 

Jpcaravelle

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Red on large starter post along with + from battery. Purple/yellow on left small post yellow/red on right small. Light blue to oil sender. On the slave solenoid yellow/red top small post, black on lower small post red on left large post yellow on right small post. Gray and black to shift interrupt switch. Coil has Purple/yellow and what I’m assuming is the purple resistor wire on positive. Gray on negative and black from distrib on negative. Tan to water temp. Alternator has orange and black then purple to red and purple/white to purple.
 

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Scott Danforth

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purple/yellow is the full 12 volts from the start circuit to the points (ballast bypass)
 

Jpcaravelle

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Jan 12, 2020
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I have put a wire from battery to coil still doesn’t crank. The motor spins but no fire (assuming everything I stated is hooked up correctly). When I get paid I’ll try to get new points. I’m sure the distributor wasn’t put in right either. I’ll have to find tdc and see if I can seat it in there. Seen alot of videos of people having trouble getting it in.
 
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