Under hood starter button schematic

Discussion in 'General Ranchero Help' started by GBH Jon, Dec 22, 2020.

  1. GBH Jon

    GBH Jon In Third Gear

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    181
    Location:
    North Devon UK
    Has anyone got a link to a wiring diagram etc for a 74 underhood starter button. Mine is not functioning. Ta.....
     
  2. 72GTVA

    72GTVA Administrator Staff Member

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    With gauges or warning lamps?

    Guessing you are referring to the solenoid switch on the passenger fender...???
     
  3. 72GTVA

    72GTVA Administrator Staff Member

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    Wiring diagram is in tech reference and articles forum, attached here for convenience:

    74 Wiring Diagram


    [​IMG]

    [​IMG]
     
  4. GBH Jon

    GBH Jon In Third Gear

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    181
    Location:
    North Devon UK
    Gauges....... Yes the manual button near the starter solenoid. I had checked those diagrams, but couldn't see it on there. Am I not reading them correctly?
     
  5. 72GTVA

    72GTVA Administrator Staff Member

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    Location:
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    Top sheet, just left and immediately below the "1974 Ranchero" label is a device named "starter relay" - that is the starter solenoid switch/relay (lets just call it the starter relay from now on for this discussion...) From the battery + pole, connected to the pole nearest the radiator support, is a ~4 gauge wire (typically black), and the ~10 or 12 gauge yellow, a 14 gauge orange/red stripe wire, and one or two other wires that may be connected to a rectangular circuit breaker that feeds options (if installed, if there aren't supplemental optional equipment you may not have additional connections. Follow the yellow from the left post to the wiring shown below right for gauges. Connected to the right hand post is the starter cable (typically ~4 gauge black). Connected to the solenoid switch on the skinny post over by the battery connection is a light blue/red stripe wire, this is the starter trigger signal wire.

    There should be an insulator junction block located on the fender apron below the starter relay, the wires on that junction block should be the 10-12 gauge yellow, a 14 gauge yellow/light green stripe, the orange/black from the alternator, yellow/white stripe (voltage regulator). Some tracing should make it a little clearer.

    A quick test of the starter relay to verify that it works, is to jump from the battery pole on the starter relay to the skinny post that the blue/red stripe wire connects - that provides a 12V signal to the relay and should cause the starter to engage.
     
  6. GBH Jon

    GBH Jon In Third Gear

    Messages:
    181
    Location:
    North Devon UK
    Solenoid/relay is fine. Just to check, this is the unit that's not working..... I assume its meant to be a starter/bump switch?
    [​IMG]
     
  7. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    That is the starter/seatbelt interlock defeat switch. It was put in as a stopgap measure to allow engine starting, if the seatbelt interlock system failed, and you couldn't start it. I have the Ford diagram, and I'll post the diagram up shortly.
     
  8. 72GTVA

    72GTVA Administrator Staff Member

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    Location:
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    I wonder if that isn't the seat belt starter interlock? There was a device installed with 1974 models that required driver and (if there was someone sitting there) passenger seat belts to be fastened before the starter switch would function. It was wildly unpopular that mid-year it was eliminated and dealers and owners could disable the functionality completely.

    None of mine had that... Someone familiar with that piece of nanny-state engineering may need to wade in... Sorry.

    Edited to add - looks like Andy may be able to give you the solution... were it me, I'd make it disappear - with extreme prejudice.
     
  9. GBH Jon

    GBH Jon In Third Gear

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    181
    Location:
    North Devon UK
    Ah..... That explains it then. Thanks for the info... The seat belt interlock and neutral safety switch have indeed been deleted. I guess that renders it redundant then?
     
  10. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Location:
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    Originally, they were jumpered to bypass them. I never tinkered with mine, as it would've given an underhood START button for maintenance. Do you still want the diagram? I was ready to post it, but it sounds like you don't need it. However, if you want them, since I really don't need them anymore, I can mail these to you over across the pond in Blighty.
     
  11. GBH Jon

    GBH Jon In Third Gear

    Messages:
    181
    Location:
    North Devon UK
    Well, as it seems it won't work now without a bit of adapting elsewhere, I may as well get a trigger starter if necessary. So probably best to save postage, but thanks for the offer and advice. Steep learning curve over here...... Lots of stuff on these motors that we don't usually have..... But to be fair, there's more room under the hood for more 'stuff' to fit...
     
  12. 1979 RANCHERO GT

    1979 RANCHERO GT In Overdrive

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    984
    I remember when those things got put on. It is meant for a mechanic to be able to push the button, then get in or reach through the window and start the car without buckling the seatbelt. If you didn't push the button it didn't start unless you buckled up, and if it didn't start the first time you had to get out and push it again. What a pain for us working at shops. It was another bright idea like the racetrack seat belts that Escorts and VWs had. It is not a remote start button.
     
  13. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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  14. 72GTVA

    72GTVA Administrator Staff Member

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    Location:
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    I think I'd still get the schematic for that and trace it through to remove it. My opinion (as worthless as anyone else's) - it was designed to prevent cars from starting if seatbelts weren't fastened and just adds a point of failure, probably when you least will find it convenient.

    Good luck with whatever you decide to do about/with it!
     
  15. Jeff B.

    Jeff B. In Third Gear GOLD MEMBER

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    112
    Location:
    Anacortes, WA
    I have this reset button on my ‘74. I’ve replaced the stock bench with buckets and it’s no longer functional. IIRC there were wires and a switch under the bench that were part of the system so I’d start there.

    My first introduction to this misguided system was traveling along within days of acquiring it and the car dies. Dead. I managed to make it to the side and all it would do was crank, no fire. Popped the hood, hit the reset button and all was good until it happened again some time later on another day. I jumped the switch and never looked back. It could have been a different story if the failures had occurred somewhere hazardous.
     
  16. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

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    Location:
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    Well, I do know there was a recall of some kind, as the owner of my Squire had told me there had been paperwork the original owner had given her detailing the recall, but she had misplaced it. Essentially, they had bypassed the underhood switch somehow, which kept the solenoid trigger always closed for starting.
     
  17. GBH Jon

    GBH Jon In Third Gear

    Messages:
    181
    Location:
    North Devon UK
    Now I now what it actually is, and the car starts fine, I think I'll leave it well alone!!
    Cheers again for the knowledge.
     
  18. handy_andy_cv64

    handy_andy_cv64 In Maximum Overdrive SILVER MEMBER

    Messages:
    11,351
    Location:
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    Cool. And if you decide to get these diagrams anyway, just let me know.
     
  19. 65restomod

    65restomod In Overdrive BRONZE MEMBER

    Messages:
    806
    Location:
    Danville,VT left NJ forever
    Found this on a Maverick site:
    bypass the interlock
    I 'm not sure that wiring colors may be the same but the connector should be the same
    [​IMG][​IMG]
     

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