67 Coupe 289 Auto starting issue

Mustang Australia

Author Topic: 67 Coupe 289 Auto starting issue  (Read 3967 times)

Offline scollist

  • Worked
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  • 65FB, 2017 GT
  • Location: Melbourne VIC
  • Name: Shane
Re: 67 Coupe 289 Auto starting issue
« Reply #25 on: November 21, 2020, 09:43:30 am »
Nailed it!!! solved.

In my earlier posted I mentioned that there was a relay under the dash near the fuse box and it looked like a factory loom. I took a deeper dive under the dash and found that relay had been deliberately added. From my limited knowledge it appears the wire running from the loom under the dash to the ignition coil had been cut and the relay put in between. This is where the wire to the break switch comes in as there was a wire spliced into the 12v switched side of the switch to the relay so when the brake pedal was pressed it supplied 12v to the relay energising it and sending the voltage to the coil. I removed the relay and wire bridged those two terminals and wouldn't you know it starts as any normal car now. i will need to do a permanent fix but I will just wait and see if I have created any other issues that that set up was masking.

Thank you all for your support and suggestions as they all really helped.

So we determined it is was a deliberate addition, and removing it makes starting the car work as per factory (your original stated problem).

But later on you mentioned that you didn't have brake lights. In removing the relay has this problem been fixed?

Offline Gabs64

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Re: 67 Coupe 289 Auto starting issue
« Reply #26 on: November 21, 2020, 09:51:40 am »
Hi Evan,

No wont start in gear neutral switch doing its job. I can only think that maybe it was set up that way to make it child proof or something like that. I might actually tuck up switch away somewhere and turn it into a kill switch set up.


Offline Gabs64

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Re: 67 Coupe 289 Auto starting issue
« Reply #27 on: November 21, 2020, 10:10:37 am »
They are back as should be but i feel that may have been a seperate issue as I got them back by playing around with the turn switch connector plug and just unscrewed and reseated the switch itself in the steering wheel around the same time i sorted out the other prob. I cant give a definite answer on that one. I have a turn switch coming (due Monday) and I will replace it anyway since I have the steering wheel off and the seats out so access is better just to be sure.