72 dart electrical.

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CLAY72dart

CLAY72dart

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Looking for help with these 2 wires that are loose in my wiring harness in the engine bay. They run off the bundle that goes to the alternator. Not sure what they are.

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Depending which wires you're referring to- brown with the ring terminal is usually coil+, the others I can't really tell the colors... that bundle contains alt. field wires, temp. sending wire, oil pressure sending wire, ac clutch wire, sometimes an electric choke wire and carb idle pulloff wire, ign. 1 and ign. 2, ground wire to rear of head, among others depending on how it's equipped.
You really need to go to Mymopar.com and download the factory service manual with all the wiring diagrams for your car. It should be the first stop for everyone before they turn a wrench on their car.
 
Professor Fate said:
Depending which wires you're referring to- brown with the ring terminal is usually coil+, the others I can't really tell the colors... that bundle contains alt. field wires, temp. sending wire, oil pressure sending wire, ac clutch wire, sometimes an electric choke wire and carb idle pulloff wire, ign. 1 and ign. 2, ground wire to rear of head, among others depending on how it's equipped.
You really need to go to Mymopar.com and download the factory service manual with all the wiring diagrams for your car. It should be the first stop for everyone before they turn a wrench on their car.
Click to expand...
I have the diagram. I wish it showed based off the wire bundles.
 
Was the car originally a V8 or slant 6.

Some of those wires look old and brittle.
 
CLAY72dart said:
I have the diagram. I wish it showed based off the wire bundles.
Click to expand...
Do you just have "A" diagram (simplified aftermarket diagram), or the full FSM set of diagrams? Those aftermarket ones are easy to use, but they don't show anything other than basic operating systems. The FSM has detailed, all-inclusive diagrams that identify wires/circuits by wire color and gauge.
 
I can't tell what color. One almost looks like it could have been temp sender, but the eyelet is obviously not factory.

"Ohm" them out AKA continuity. Looks like you have the harness separated from the bulkhead, right? Find what pins on the bulkhead end, give you a ping on the continuity checker from that wire, and look up what that pin is.
 
Get a new engine wiring harness, should be self explanatory. The insulation on my '72's engine harness was brittle, into the trash box with all of the other wiring harnesses that I have replaced.
 
I have the MOTOR book for up to the 1971s If you think that could help I can send you a copy of it. but no guarantees
 
Professor Fate said:
Do you just have "A" diagram (simplified aftermarket diagram), or the full FSM set of diagrams? Those aftermarket ones are easy to use, but they don't show anything other than basic operating systems. The FSM has detailed, all-inclusive diagrams that identify wires/circuits by wire color and gauge.
Click to expand...
I have the FSM diagram.
 
Small block? given the location of the wire next to the alternator wires what could it be except the temp sending unit???
 
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Alternator output (12 gage black) and if one is green anbd the other blue those are the field connectors.
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The alternator output has a protective cover so it does not get accidently grounded.
It's connected to the battery positive. As long as the battery is connected, these wires are always hot!
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R6 is AlteRnator output.
J1 is feed to the ignition switch. (J is a substitute for I because it won't be confused for the number 1)
The other wires are the feed to the fuse box hot buss, and the feed t othe headlight switch B1 terminal.
The only protection against grounding the battery is a fusible link.

The field wires work like this. The blue feeds power to the rotor, and the green connects to the voltage regulator which controls the current flow needed to make the electro-magnetic field.
1972 Basic power scheme (with points ignition)
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Typically.
A is Battery outputs (and recharge).
R is Alternator circuits. R6 is alternator output.
J1 is power to ignition switch
J2 is ignition run (includes power to voltage regulator)
J3 is ignition feed only when key is in start.
Q is Accessory feeds
Q2 is switched accessory feed - (pretty much everything which requires key on other than ignition)
L is typically exterior Lighting
H is usually Horn.

So know you know what they do as well as where they go.
 
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