1974 dart sport 360 won’t start with key but will start from starter relay
- Thread starter 1967bcuda
- Start date
-
I have had situations where a car with a fully charged battery starts fine with the key but once the battery charge drops off, the only way to start it is to turn the key to RUN and cross the terminals on the relay. In that case, I blame seasoned wiring. The ignition switch wiring connector is a place that is susceptible to oxidation and corrosion.
Dfr360cuda
Diagnosis... Plum Crazy.
Is the relay picking up ?
Check the smaller wire for 12 volts when the key is turned.
Check the smaller wire for 12 volts when the key is turned.
I have had several junction boxes quit working.
The will start by jumping with a screw driver across
the terminals. The box is the problem the majority
if the time. They are cheap and available from most Auto Parts!
The will start by jumping with a screw driver across
the terminals. The box is the problem the majority
if the time. They are cheap and available from most Auto Parts!
j par
Well-hung Member
This happened to my son with his 76 Power Wagon for about 3-4 months until I finally came out to Colorado and visited him and made him to buy a test light (he's an auto mechanic...) And it was a simple loose connection at the starter solenoid...
67Dart273
Well-Known Member
Do you mean it will not crank the engine or do you mean it will not fire when cranking with the key
YOU LIKELY HAVE tripped the awful, the hateful SEAT BELT INTERLOCK
Look under the hood on the driver side apron for a box like a horn relay with a PUSH BUTTON reset button. See if that "fixes" it. THEN find the two "yellowish" wires in that connector and splice them permanently together
67Dart273
Well-Known Member
If that does not do it.......
Get yourself a 74 service manual. In leu of that I created this reduced size wiring section of the manual, but I recently discovered it might have a flaw. But it is fairly complete
https://www.forabodiesonly.com/mopar/attachments/74vlwirings-pdf.1715779008/
For everything EXCEPT wiring, go over to MyMopar and download the 73 service manual.
Service Manuals – MyMopar
Also there, download the two page aftermarket wiring diagram for 74. I do not believe, however, that it shows the seat belt interlock stuff. Those diagrams tho, can be easier to follow
Wiring – MyMopar
The electrical path for the starter relay is follows:
From the key, in "start" the YELLOW wire goes through the bulkhead connector, through the seat belt interlock, and over to one of the "push on" flag terminals of the magnetic coil of the starter relay. Through the coil, and out on (if automatic) wire goes down the firewall, down to the center terminal of the transmission neutral safety switch which GROUNDS in neutral or park. If a stick car, the wire is fed back into the interior through a single wire grommet and connects to the clutch pedal switch. So that path pulls in the relay
The contacts of the relay are the "big stud" which is ALWAYS hot and connects to the battery. When the relay closes it sends power down the no12 or no10 wire connected to the "big square" screw terminal and down to the starter solenoid, pulling in the starter
Once you "punch" the reset button, and if it still will not crank, put your test lamp or meter on the yellow wire at the starter relay and see if you get power with key in "start." If so, move to the opposite "push on" terminal and see if there is power there. If so, the neutral switch is NOT grounding. While holding the key to "start" wiggle the shifter through neutral and back to park, listen for a click or other "try" for it to operate.
If that shows OK and or if you can hear the start relay "click" then the contacts are bad, since you already jumped that point (right) and got the starter to crank?
Get yourself a 74 service manual. In leu of that I created this reduced size wiring section of the manual, but I recently discovered it might have a flaw. But it is fairly complete
https://www.forabodiesonly.com/mopar/attachments/74vlwirings-pdf.1715779008/
For everything EXCEPT wiring, go over to MyMopar and download the 73 service manual.
Service Manuals – MyMopar
Also there, download the two page aftermarket wiring diagram for 74. I do not believe, however, that it shows the seat belt interlock stuff. Those diagrams tho, can be easier to follow
Wiring – MyMopar
The electrical path for the starter relay is follows:
From the key, in "start" the YELLOW wire goes through the bulkhead connector, through the seat belt interlock, and over to one of the "push on" flag terminals of the magnetic coil of the starter relay. Through the coil, and out on (if automatic) wire goes down the firewall, down to the center terminal of the transmission neutral safety switch which GROUNDS in neutral or park. If a stick car, the wire is fed back into the interior through a single wire grommet and connects to the clutch pedal switch. So that path pulls in the relay
The contacts of the relay are the "big stud" which is ALWAYS hot and connects to the battery. When the relay closes it sends power down the no12 or no10 wire connected to the "big square" screw terminal and down to the starter solenoid, pulling in the starter
Once you "punch" the reset button, and if it still will not crank, put your test lamp or meter on the yellow wire at the starter relay and see if you get power with key in "start." If so, move to the opposite "push on" terminal and see if there is power there. If so, the neutral switch is NOT grounding. While holding the key to "start" wiggle the shifter through neutral and back to park, listen for a click or other "try" for it to operate.
If that shows OK and or if you can hear the start relay "click" then the contacts are bad, since you already jumped that point (right) and got the starter to crank?
Last edited:
DionR
Well-Known Member
Not certain, but I think the key has to be on when the button under the hood is pushed or the safety relay doesn’t do anything.
Might try buckling the seatbelt, too. Could be the interlock system is working like it was designed to.
Might try buckling the seatbelt, too. Could be the interlock system is working like it was designed to.
The one year only thing interrupts the positive signal to relay ( yellow wire ). You also need the ground path through NSS. So if it wont start in park, try neutral and wiggle the shifter.
Too often we have seen column shift automatics, after column had been lowered for some other service and that switch adjustment had changed. Any year model
Too often we have seen column shift automatics, after column had been lowered for some other service and that switch adjustment had changed. Any year model
66 Valiant wagon
Well-Known Member
If you have a 4 prong ballast resistor it could be a bad connection there as well. If you have corrosion or a bad connection it will act like you describe.
DionR
Well-Known Member
I don’t think the ballast resistor has anything to do with the starter engaging. The ballast resistor can cause a no start issue, but not a no crank issue.
Now, I am reading into it as the OP isn’t spelling out which it is, but the fact that he can start it at the starter relay implies (to me) that the problem is a no crank issue.
66 Valiant wagon
Well-Known Member
I read it as it cranks with the key but won't start there?
1967bcuda
Active Member
- Joined
- Aug 5, 2009
- Messages
- 36
- Reaction score
- 0
-
