won't start....

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Abodysrule

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I pulled my slant six and swapped it for a 360 magnum. I was very careful not to change anything in the wiring, I marked everything and simply reatttached. I did put a different neutral safety switch in the new tranny. When I turn the key I get intermittent power, i.e. my volt gauge in the dash shows battery power intermittently. But even when it's showing power, the ignition wire to the starter isn't getting power when I turn the key. I tried in park and in neutral. My battery is good, I bench tested the starter, it's good. My headlights, flashers, etc. all work. Is this perhaps a bad ground to the engine? Any ideas? Everything worked perfectly prior to swap.

This is a '67 dart, A904.

Note: I also note that my horn isn't working. I hear the relay click, but no horn. Perhaps unrelated, but just fyi.
 
How bout power to the start relay? Is it a green wire? I forget I think blue is to the coil and green to the start relay however should get power when key is turned.
 
Is there power at the starter relay? You can jump it with a screwdriver there to test.
Did you ground the engine to the body?
 
OK, I'll check that next. I don't think it's the ground, because I have two separate grounds to the engine, one to the firewall and another to a negative lug that goes directly to the battery negative.
 
Yes, the positive to the starter is energized, its the wire from the starter relay to the starter that's not energizing. Yes, I have two separate grounds to the engine, one to the firewall and one from the starter body to a lug that goes to the negative battery terminal.
 
i would consider the neutral safety switch since it is the only part that is new
 
Do you have a newer transmission than (I forget, ) 69? The older autos must have the SINGLE pin neutral switch, the newer ones 3 pin. The center pin has a wire that runs up and grounds the starter relay in park/ neutral

Could be wrong neutral switch, shifter/ linkage not correctly adjusted or something amiss inside the transmission

And could be electrical.

Simple circuit: Twist the key to start, the yellow "start" wire comes alive and feeds power TO the start relay on one of the flag "push on" terminals. Power goes through the magnetic coil, comes OUT the other flag terminal, runs down the wire to the neutral switch which should be ground.

So to troubleshoot, try removing the NSS wire and clipping a jumper to that starter relay terminal and ground. After making certain you are in P/N, see if it cranks.

If not make certain the yellow "start" wire is hot with key in start.

Also clean your batter terminals, check starter relay stud and starter big stud for tight connections, etc.
 
Thanks this is great stuff. The neutral safety switch is single pin. Does your jump scenario you just described still hold true? Let's see on an A904, park is all the way back, right? I can check the linkage as well.
 
Depending on the 904 there are SEVERAL different rooster combs in the transmission.

The wrong one will not ground with the wrong switch in place.

Basically...

If it originally had a 3 pin and you put a 1 pin in it won't work. And visa versa



Easy to test.

Get you DVM put it on diode mode ( makes a tone even the leads are touching each other.)

Hook one to the wire that goes to the starter switch wire and the other to battery negative.

Then run the trans through its positions from park to low

Also get a wiring diagram mymopar.com free download or classiccarwiring.com best 25.00 you can spend
 
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Abodysrule said:
Thanks this is great stuff. The neutral safety switch is single pin. Does your jump scenario you just described still hold true? Let's see on an A904, park is all the way back, right? I can check the linkage as well.
Click to expand...
No Park is (console) all the way forward, (column) all the way "up." Or are you talking about the transmission lever? I don't remember LOL You can check by finding if it's in park
 
Transmission lever.

Oh, I had a shop build this A904 for me. which comb is a good point, maybe a 3 prong NSS is the right one. I'll have to ask the builder which NSS I should be using.....

Dana67dart, can you elaborate on using the DVM. What am I listening for as I run the lever through its positions. Which wire to the starter switch?
 
OK, so I wrote to the A904 builder and asked which comb he used in the A904. Let's assume that is the issue, that is, I put a 1-wire NSS where a 3-wire NSS was appropriate (the A904 has the comb for the 3-wire NSS).

I have the reverse light switch on the column, it works. What do I need to do to change over to the 3 prong NSS? Specifically, assume I have the 3 prong NSS and the pigtail. Which of the 3 wires do I use, and how do I hook them up?

B
 
The outer two on the 3 prong are for reverse lights, and the center pin is the NSS. You don't HAVE to use the two reverse ones if your present one (which is on the shifter) works.
 
Does your relay look like this? Unplug terminal and jump terminal to ground and see if it cranks over.

Starter relay.jpg
 
Yeah, that's my relay. If I have the wrong NSS, can't I just ground the wire that goes to it and see if it cranks (in park, no coil wire on)?
 
^^Do what kendog posted^^ Ground that terminal, or take the NSS wire's terminal to the NSS and clip that to ground.
Make sure the selector is in Park.
Turn the key and if the starter cranks then you know the relay wasn't getting grounded.
1718285154240.png

Abodysrule said:
But even when it's showing power, the ignition wire to the starter isn't getting power when I turn the key. I tried in park and in neutral. My battery is good, I bench tested the starter, it's good. My headlights, flashers, etc. all work. Is this perhaps a bad ground to the engine? Any ideas?
Click to expand...

Abodysrule said:
I also note that my horn isn't working. I hear the relay click, but no horn.
Click to expand...
Horn is power is joined to the main circuit at the alternator.
IF the battery is charged and in good condition, then the connection or wiring has too much resistance for the higher current needed to run the horns.
1718285179995.png
1718286375440.png


1718285600975.png
 
Abodysrule said:
Dana67dart, can you elaborate on using the DVM. What am I listening for as I run the lever through its positions
Click to expand...
What others have stated will work to show the issue.

But...

The NSS path is starter relay terminal to the NSS, when the NSS is in the correct position it grounds out.

With the DVM in continuity mode (beeps when the leads are connected) and connected to the wire that goes to the NSS and battery negative, when you run the trans lever through its positions the meter should beep in 2 places, N and P.

If it doesn't beep or beeps in the wrong position you know you have an issue with the switch or the rooster comb
 
OK, I heard back from the builder. He said they used an insulated comb which is for the 3 prong NSS. He did note that it will work with a 66-69 single prong switch, but not other single prong switches. My new single prong switch did look different than my old single prong switch, perhaps I have the wrong one. Regardless, I'll test it today and see if that is the issue.
 
Confirmed, I jumped the NSS wire to ground and it turned right over. Just need to know which NSS I should use.


...and checking the horn circuit next.
 
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