No power on “cranking” cycle from key-73 Dart

[Jacob Moparman13]

Hello, I have a 73 Dart with a slant. (4 door, not that it matters) and I’ve run into an issue where I cannot get it to start when I turn the key. I have no problem getting it to crank/run by jumping the terminals on the start solenoid with a screwdriver as long as the key is in the “run” position.

This was not a problem for the first year I owned it, and I’m wondering if I jumped the solenoid one time to try and set the motor to TDC if that fried something that I didn’t see.

When I put the key in the ignition and turn it to crank, I lose power to everything until I let off the key.

Where would a good starting point be to look? All fuses that have been in the car since I aquired it are not blown, although it appears the first two slots do not have any fuses in them.

(Should be noted, any extra wiring you see in the photo was not my doing. It’s a bit a rats nest as you can tell LOL)


73 Dart, slant six/904
non tilt/non telescoping column.

 

[Dubob]

By jumping across the terminals you’ve verified the power from the battery to the solenoid is good if it cranks. Check for voltage on control wire at solenoid terminal, should be yellow wire. Clean mounting area and solenoid mount, that’s where it grounds. This is where I’d start. If there’s not voltage on control wire at solenoid then you’ll need to start back tracking through the neutral safety system to the ignition switch to see where power is lost. Have you tried starting in neutral? Also may want to go to Service Manuals – MyMopar to download service manuals for your car.

Sorry was not fully awake when I posted. Corrected my error.

 

[RustyRatRod]

This almost sounds like a loose connection. Try wiggling and pushing in the main firewall connectors and see if that does it.

 

[Dartswinger70]

does that car have the 10 pin connector at the column?

 

[67Dart273]

HERE is how that works

Ma uses the starter relay to relieve the key switch from the high current of the starter solenoid, as well as incorporating the neutral start safety into the mix

The two small "flag" push on terminals are the relay coil. The yellow, connected to one, is the "start" voltage coming from the key switch when you twist the key to "start." But the second terminal on the relay is to ground the relay coil. That wire goes down the firewall and connects to the center terminal on the neutral switch, which has 3 terminals. the outer two are for reverse lights.

SO TAKE a light or meter, and back probe the yellow wire. See if you have power when you twist the key to start

If so, try wiggling the shifter from park to neutral and back while holding the key to start. Any click, noise shows an attempt to crank. Either the linkage is out of adjustment, the switch is worn, maybe the electrical connector is loose.

If that does nothing, remove the dark wire from the relay --the one going down to the transmission--and use an alligator clip jumper to ground that relay terminal. BE CAREFUL You just bypassed the neutral safety. Making sure the lever is in park, try to crank the engine

This is a simple circuit. Power comes to the relay coil on the yellow, through the coil, and down to the neutral safety switch where it is grounded in park or neutral

 

[Jacob Moparman13]

does that car have the 10 pin connector at the column?

I’d have to look, will do so shortly

 

[Jacob Moparman13]

HERE is how that works

Ma uses the starter relay to relieve the key switch from the high current of the starter solenoid, as well as incorporating the neutral start safety into the mix

The two small "flag" push on terminals are the relay coil. The yellow, connected to one, is the "start" voltage coming from the key switch when you twist the key to "start." But the second terminal on the relay is to ground the relay coil. That wire goes down the firewall and connects to the center terminal on the neutral switch, which has 3 terminals. the outer two are for reverse lights.

SO TAKE a light or meter, and back probe the yellow wire. See if you have power when you twist the key to start

If so, try wiggling the shifter from park to neutral and back while holding the key to start. Any click, noise shows an attempt to crank. Either the linkage is out of adjustment, the switch is worn, maybe the electrical connector is loose.

If that does nothing, remove the dark wire from the relay --the one going down to the transmission--and use an alligator clip jumper to ground that relay terminal. BE CAREFUL You just bypassed the neutral safety. Making sure the lever is in park, try to crank the engine

This is a simple circuit. Power comes to the relay coil on the yellow, through the coil, and down to the neutral safety switch where it is grounded in park or neutral

I did the jumper after tracing the wire you described, starts off the key!!!!
So does that mean I have a break in that wire somewhere? Or a bad neutral safety switch?

 

[68Bee]

Yes, could be either one.

 

[Jacob Moparman13]

Yes, could be either one.

Let’s hope it’s just a break in the wire, I can handle that no problem. But the neutral switch is 1/2” away from the exhaust pipe, that would not be fun! Might just end up running that jumper to a switch under the dash, and making it almost a theft deterrent!

 

[ESP47]

If you have a multi meter that has the little buzzer sound to test continuity, you can unplug the harness from the neutral safety switch and clip your meter onto each side of the wire. If there's continuity, you'll hear the buzzer sounding. Then shake the wire around and see if the buzzer cuts out. If it does, then you have a break in the wire that will give you intermittent problems.

Odds are more likely in favor of the NSS being bad.

 

[67Dart273]

I did the jumper after tracing the wire you described, starts off the key!!!!
So does that mean I have a break in that wire somewhere? Or a bad neutral safety switch?

Or just linkage out of adjust. Connect it all back up. Hold the key to "start." Now wiggle the lever from park to neutral, see if it cranks, tries to, or clicks like it is "trying."