Daughters 72 dart not turning over

-

Chub380

Well-Known Member
Joined
Aug 17, 2020
Messages
151
Reaction score
44
Location
Montana
Two times in the last month my daughters car would not turn over, battery is new starter is new. I was thinking maybe there is a switch that lets the car know if it’s in gear or not that’s failing can anyone confirm if there is such a device and where it’s located? The car is a 1972 Dodge Dart 318 with a 904 trans thanks a lot guys
 
Try putting the shift selector in neutral & see if it starts. The neutral safety switch is the switch you are referring to.
 
As above^^

Neutral safety switch is on the side of the trans on driver side. 3 pins. Outer two are reverse lamps, center one is NSS and it is grounded in P or N. Look at the starter relay. Two "push on" connectors

Pull the dark colored one, the yellow one is the "start" power from the key switch. Try grounding the tab on the relay that you pulled the wire off and see if it will crank. BE CAREFUL that it is NOT in gear

If it does, then either the NSS is out of adjustment or bad, or bad wire. If it will not crank, then it's starter relay, wiring to the ignition switch, or IGN switch bad

Wander over to MyMopar. You can download free service manuals there
 
The terminal with the G.
On a '72 w/ automatic the wire may be a brown with yellow stripe.
upload_2022-4-4_18-38-52.png


Break or partial break could be in the wire to the switch, or the connectors, or the neutral safety switch itself. Making a jumper going from the G terminal to a ground will eliminate those. If so, then you where to investigate.

Its supposed to work like this:
When the key is in Start position, power becomes available in the yellow wire going to the I terminal.
When power goes from the I terminal through the G terminal to ground, an internal switch connects the Battery terminal to the Solenoid terminal.
Power then flows to the starter solenoid in the starter.
upload_2022-2-24_10-5-51-png.png
 
Thanks you guys now if it happens again I’ll have a little knowledge on the subject. Mattax is that the neutral safety switch in your picture?
 
The NSS is "depicted" AKA drawn in at far bottom right in the top photo, labeled "NSS". The item that is PICTURED is the starter relay.
 
How this all works and why

Starter solenoids draw a fair amount of current. Instead of, like GM, using the key to directly fire the solenoid, Ma chose to use that starter relay which also incorporates the NSS. This relieves the key switch of a lot of current. The two push on terminals are the relay magnetic coil, the big stud and the "square" screw terminal are the contacts. The "big stud" is used as a battery junction point and also feeds that contact, and the "square screw" one is a rather large (no12 or 10) wire which goes down to the solenoid

The NSS must be grounded (in park or neutral) before the coil sees a complete circuit from the ignition switch, through the coil, to ground.

This is a pretty reliable system, and is still used (last I knew) in the RAM trucks, except the relay is now a "Bosch" plug in unit in the main power distro box.
 
Starter Relay is next to the battery
upload_2022-4-5_22-12-26.png

Photo from 1972 formal black 340 duster "survivor"
and yes I took a screenshot by opening 'view image in new tab' to avoid pb's annoying watermark. It's not their photo!

NSS circled
upload_2022-4-5_22-27-6.png

from Wire holder

e7eb2ab2-850d-4e9a-8798-4ed0f45b5966-jpeg.jpg


'69 wire routes like this. '72 will be similar
upload_2022-1-12_18-8-56-png.png
 
-
Back
Top