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1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1970 Mustang => Topic started by: RocketScientist on October 25, 2017, 09:48:24 PM

Title: hazard button on 1970 turn signal wiring harness
Post by: RocketScientist on October 25, 2017, 09:48:24 PM
I have two turn signal wiring harnesses for my Nov 15, Dearborn 1970 B2 (std interior) and they have different knobs/buttons that activate the emergency hazard lights. One has a square tab (off a Dec 69 Grande) and the other has a round button (off a Mar 70 6-cylinder).

I was wondering if this was due to a production change or if there is one specific to my car.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: J_Speegle on October 25, 2017, 10:01:08 PM
First thing that comes to mind is the possibility of it being a service replacement turn signal switch is the reason for the difference. Noticed this years ago...... and allot of the switches have been replaced over the years. But will look through my pictures while at the same time we'll get input from others. Guessing Ed would know
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: J_Speegle on October 25, 2017, 10:54:30 PM
Ok checked my files and I was surprised the number of shots I had with this detail since I don't normally take many interior shots of cars.

What I found focusing only on 70 Dearborn built examples

The T style with the writing on style of knob I found only  0F14273x (Possible Dec build) & 0F170xxx (Possible April build)

The round knob style I found through out the production year. Earliest 0F10173x (likely first month car) to the latest of 0F20215x (Possible June build) Some have possible build dates between the two vins posted with the T style knobs mentioned above which

Did not include restored cars but since this a commonly service part the chances of some of my examples having been changed out exists.


0F10173x - Round
0F10301x - Round
0F10865x - Round
0F11764x - Round
0F12017x - Round
0F12303x - Round
0F12291x - Round
0F13002x - Round
0F14098x - Round
0F14273x - T
0F1516xx - Round
0F157xxx - Round
0F170xxx - T
0F170xxx - Round
0R17366x - Round
0F17465x - Round
0F20215x - Round
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: RocketScientist on October 26, 2017, 12:15:55 AM
I did not consider that one might be a service replacement. The round knob style has all the paper tags still attached but the T-style switch has no identifying tags (despite looking in good condition) and this may lend weight to your theory.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: cobrajet_carl on October 26, 2017, 10:52:23 AM
Tilt switch is different from fixed. All of my original tilt switches have round knobs, but they are before 1/1/70. Service switches have rectangular.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: J_Speegle on October 27, 2017, 11:14:25 PM
Tilt switch is different from fixed. All of my original tilt switches have round knobs, but they are before 1/1/70. Service switches have rectangular.

Understand the switches are different - are the knobs?   Don't think so but want to hear what you've seen

Could find an old picture of either in NOS/service replacement form in my files
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: cobrajet_carl on October 28, 2017, 03:40:13 PM
I guess my phrasing was nebulous. I think all original switches, tilt or fixed, had round knobs. I do have a mostly original fixed wheel Dearborn December 69 with a well worn rectangular switch, but I would have to pull the wheel to see if it is original. A January 70 San Jose fixed has a round switch.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: J_Speegle on October 28, 2017, 06:07:31 PM
I guess my phrasing was nebulous. I think all original switches, tilt or fixed, had round knobs. I do have a mostly original fixed wheel Dearborn December 69 with a well worn rectangular switch, but I would have to pull the wheel to see if it is original. A January 70 San Jose fixed has a round switch.

Thanks - that was my conclusion also - Thanks again
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: Mike_B_SVT on November 01, 2017, 09:36:55 PM
My understanding is that for '70 at least, the round switch is right, and there is an "early" and "late" version of the switch / harness assembly.

http://www.mustangandfords.com/how-to/interior-electrical/1501-how-to-identify-1970-1973-mustang-turn-signal-switches/

If you need part numbers for the '70 turnsignal switch versions, I can get them.  Went through the hoops 2 years ago when I replaced my switch.  Aaaand now I'm doing it again!  Lucky me!


Title: Re: hazard button on 1970 turn signal wiring harness
Post by: RocketScientist on November 02, 2017, 12:07:29 AM
Thanks Mike but I'm OK with numbers. I had a good looking switch but it now seems to be a service replacement. I am lucky that I found an original harness out of a donor car last week and the differences between the two had me confused. The million dollar question will be if the donor harness will actually work!

Has anyone tried swapping over the switch to a service replacement harness. Then you would have the looks of old but the serviceability of a new unit.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: cobrajet_carl on November 02, 2017, 01:00:43 PM
Thanks Mike but I'm OK with numbers. I had a good looking switch but it now seems to be a service replacement. I am lucky that I found an original harness out of a donor car last week and the differences between the two had me confused. The million dollar question will be if the donor harness will actually work!

Has anyone tried swapping over the switch to a service replacement harness. Then you would have the looks of old but the serviceability of a new unit.
I think that on January 1 1970 an ignition key warning buzzer was added.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: Mike_B_SVT on November 02, 2017, 01:21:10 PM
Thanks Mike but I'm OK with numbers. I had a good looking switch but it now seems to be a service replacement. I am lucky that I found an original harness out of a donor car last week and the differences between the two had me confused. The million dollar question will be if the donor harness will actually work!

Has anyone tried swapping over the switch to a service replacement harness. Then you would have the looks of old but the serviceability of a new unit.

From going through Cougar taillight troubleshooting, my understanding is that the wires at the switch assembly are rivetted in.
http://www.thuntek.net/cougars_unlimited/TurnSignalSwDiagnosis.pdf

But I was thinking about the same thing.  I'll now have 2 bad switches in my collection, so if I can figure out a good way to simply repair them, that would save some dough in the future, while still leaving me with an original-appearing hazard switch and harness.

I don't see why you couldn't drill out the rivets, repair the switch, then re-rivet it.  Maybe add some solder in there to give better continuity and longevity?

West Coast Classic Cougars has a video on repairing the cam portion of the switch as well, which might add some useful knowledge.
https://www.youtube.com/watch?v=ddxBfWYifQc

Good luck, and keep us posted on how your switch repair / conversion turns out!


I think that on January 1 1970 an ignition key warning buzzer was added.

I'm not sure about that.  My Oct '69 built Cougar has a key buzzer and it was still sporting the original switch.  The previous owner had kindly cut the buzzer wire down at the connection, so I had to repin it.  However, my replacement NOS switch did not come with a buzzer, so I had to pull it through the harness sleeve and swap it over to the new switch.

Title: Re: hazard button on 1970 turn signal wiring harness
Post by: RocketScientist on November 03, 2017, 03:04:58 AM
Does that mean that the Cougars got the buzzer before the Mustang? I didn't consider the buzzer operation and so that seems to be another complication with the switches - no wonder it is so difficult to get something that is correct.

Those links are great which means I can test a switch before installing it. Previously I thought the only way is to stick it in and hope for the best.
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: Oneowneraquaboss on November 21, 2017, 04:22:18 PM
I don’t come here or any forum too often but killing time today and seeing this post reminded me of the issues concerning the hazard button when these cars were new. I can agree with the findings here on the round versus rectangle buttons and do know my BOSS had the round one when new and still does. The thing that no one has touched on is the fact that the two operate completely opposite of each other and from what I figure is the reason for the change. As us older folks can remember all one had to do to activate a hazard switch was to grab it and pull out but this was the change that came about with the rectangle buttons. You see, the round buttons were activated by pushing in to activate and pulling out to cancel and thus the problem. I can remember many times exiting the car and as I was walking away I’d look back only to notice that the flashers were flashing away. The location of the button is such that it was very easy for your right leg to push the hazard button in when exiting the car. I know that I complained about it to the dealer during service calls and can’t believe that I was the only one with the problem and thus the need for a change. Rich
Title: Re: hazard button on 1970 turn signal wiring harness
Post by: cobrajet_carl on November 21, 2017, 06:24:38 PM
Wow, never thought of that! Obvious from my pictures that the round knob is out and the rectangular is in.