NSS / Clutch SS wiring question... confused

[Mopar92]

Ok. The V8 swap and trans swap is done. We are ready to start it tomorrow. I wanted to try to be safe and make the clutch safety work. I like it when stuff works as it should anyway. OCD I guess. Anyway, I put on the 4 speed two prong. Reverse light work as they should. I simply just cut the yellow wire and left it in place at the plug. Now, up at the relay... that same yellow and brown wire is hit with a test light. Hmmm. Anyway, I ran a wire from the clutch safety switch to that terminal and the starter bumps with the clutch as it should. The only reason I’m questioning this is that the wire for the auto trans is 12v hot. The wire from the clutch obviously is not. And it all works. What am I missing? I used this diagram for reference. It all works it just doesn’t make sense that the factory auto trans wire is hot and the clutch SS is not yet it works.

 

[67Dart273]

The yellow going directly to the flag terminal on the starter relay is powered ONLY when the ignition switch is twisted to "start." In fact that is the start and finish to that wire.

The two flag terminals are the magnetic coil terminals of the relay, "what pulls it in." There are only TWO types of relays (regardless of changes of mounting brackets) that were used over the years in these girls..................

1.....Before clutch switches, AKA up through 1969, the relay only had ONE push on flag terminal. The other end of the coil was grounded through the bracket

2....All automatic cars, and those stick cars with clutch switches used the relay with TWO flag terminals.

Whether automatic NSS, or "stick" clutch switch, that wire going from the second relay flag terminal to the clutch/ NSS switch IS GROUNDED when the switch activates. So the key is twisted to start, and if the clutch is depressed, the other terminal is grounded...........and it cranks

 

[67Dart273]

You threw me when you said you "cut the yellow wire at the plug" You cut WHAT yellow at WHAT plug?

The wire going to the CENTER pin of the (automatic) NSS should NOT HAVE BEEN yellow

 

[Mopar92]

Maybe I’m too tired to be typing. Sorry guys. I guess it’s brown with maybe a yellow tracer. The only NONE black wire AT the reverse light plug on the trans itself. I had an NOS 2 prong for the Manual. That’s what I clipped... and I connected the Black with white tracer and black solid together. The reverse lights work as they should. I ran a dark green wire I had in the electrical drawer (to stay with the wiring diagram colors) from the clutch switch brown/yellow wire spade. I just pulled off the lower right yellow and brown off the relay and hooked my clutch wire to it. Works as it should. I just don’t understand how that yellow and brown is hot on run and works.

 

[tonysrt]

For years people started stick cars without having to step on the clutch. Now some genus says we have to step on the clutch to start. Is it the same guy who said we must step on the brake to put the car in drive? People are still mistaking the brake for the gas pedal and running into buildings and people. I disconnected my clutch interlock switch because I don't want to put pressure on the crank when it cranks over. When I get in the car I grab the stick and make sure it's in neutral and fire it up. After 33 years never had a problem or even a close call. Just pay attention and everything will be fine.

 

[Mopar92]

That answered none of what I asked. Thanks.

 

[67Dart273]

I just don’t understand how that yellow and brown is hot on run and works.

It should not be. The yellow is what would be hot, unless you have a harness "cross", pull the brown loose and check it separate. It should only go one place........from one of the flag terminals on the relay, to the clutch switch. If the yellow is hot in "run" you either have a wiring harness problem or something wrong in the ignition switch.

 

[jos51700]

If it has 12V, it's for the reverse lights. The clutch should connect the starter relay pull-in to ground when you step on the pedal.

And agreed, your crank thrust bearing will thank you: Save the no-oil-pressure crank end loads for someone else and start in Neutral with switch bypassed.

 

[67Dart273]

If it has 12V, it's for the reverse lights. The clutch should connect the starter relay pull-in to ground when you step on the pedal.

And agreed, your crank thrust bearing will thank you: Save the no-oil-pressure crank end loads for someone else and start in Neutral with switch bypassed.

If it operates normally with the key, then it's not the reverse circuit. If he had that connected, the starter would operate whenever the clutch is depressed, without the ignition switch being in start

And of course the reverse lights would not work if wired that way

Or have I completely misunderstood the symptoms?

 

[jos51700]

The starter relay cannot operate unless the pull in coil is grounded first. In automatics this occurs in nss, in stick cars the clutch pedal switch does the job.
When I bypassed my clutch switch, I ran the clutch switch wire straight to ground.

That addresses condition one.

Then when the key is turned, power is applied to the relay pull in (and grounds through the switch), and pulls the relay, jumping the always - hot side to activate the starter.

That addresses condition two. Both conditions must be meet for starter motor actuation.

I understood this to be the functionality that the op wishes to restore.

 

[Alan J Odze]

If it operates normally with the key, then it's not the reverse circuit. If he had that connected, the starter would operate whenever the clutch is depressed, without the ignition switch being in start

And of course the reverse lights would not work if wired that way

Or have I completely misunderstood the symptoms?

I have a 73 Dart Sport 340 H/A833 tranny no reverse lights. I found someone cut the wire to the reverse light in the car. Can’t find the other end though. Question though since the reverse light inside the car is cut would that affect the reverse lights not illuminating outside the car? Thank you

 

[Mattax]

I have a 73 Dart Sport 340 H/A833 tranny no reverse lights. I found someone cut the wire to the reverse light in the car. Can’t find the other end though. Question though since the reverse light inside the car is cut would that affect the reverse lights not illuminating outside the car? Thank you

Go to www.mymopar.com and download the Service Manual. There are wiring diagrams in the electrical section. You will have to manually highlight trace and redraw the wires you are interested in.

You got lucky today. Not too long ago we walked someone with a '73 through a hunt for a short in that circuit.

In '73 the reverse lights are powered from this circuit which also has heater, radio, and turn signals.
The connections to the backup circuit are highlighted in yellow.

The numbers and lettersinside the ovals are connector references.
CE2B = Connector Engine 2 cavity B. This is the multi-connector through the firewall.

Green arrows point tothe positioning bumpouts. That will help you orient the cavity correctly when looking at the real thing.
B1 = Backup wire 1 18 BK = 18 gage Black.

CE 40 is the next connector and is also in the Engine compartment.

That leads to the harness going to the switch.

How it works:
When the key is on, power is available in that circuit the B1 is connected to.
When the switch in the transmission (or some manual transmissions have it on the shifter) is in reverse, the power goes through the switch, back through the return wire B2 to the Bulkhead multiconnector. It connects to another B wire going to the body harness.

On my car, which is an older model, the body harness connection is behind the left kick panel. The harness to the tail runs back next to or over the left rear inner fender.
The '73 shop manual will have that info.

 

[Alan J Odze]

Go to www.mymopar.com and download the Service Manual. There are wiring diagrams in the electrical section. You will have to manually highlight trace and redraw the wires you are interested in.

You got lucky today. Not too long ago we walked someone with a '73 through a hunt for a short in that circuit.

In '73 the reverse lights are powered from this circuit which also has heater, radio, and turn signals.
The connections to the backup circuit are highlighted in yellow.
View attachment 1715982497

The numbers and lettersinside the ovals are connector references.
CE2B = Connector Engine 2 caity B. This is the multi-connector through the firewall.
View attachment 1715982500
Green arrows point tothe positioning bumpouts. That will help you orient the cavity correctly when looking at the real thing.
B1 = Backup wire 1 18 BK = 18 gage Black.

CE 40 is the next connector and is also in the Engine compartment.
View attachment 1715982502

That leads to the harness going to the switch.
View attachment 1715982501

How it works:
When the key is on, power is available in that circuit the B1 is connected to.
When the switch in the transmission (or some manual transmissions have it on the shifter) is in reverse, the power goes through the switch, back through the return wire B2 to the Bulkhead multiconnector. It connects to another B wire going to the body harness.

On my car, which is an older model, the body harness connection is behind the left kick panel. The harness to the tail runs back next to or over the left rear inner fender.
The '74 shop manual will have that info.

THANK YOU SO MUCH!!!