Ignition switch positions

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Spechti

Well-known member
Joined
Mar 8, 2011
Messages
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Location
Hamburg, Germany
My Car
1971 Mustang Mach 1 (under restoration), 1973 Lincoln Mark IV (show boat)
Hi guys,

I am just doing the adjustments on the ignition switch on my 71 Mach 1 and I would like to know if the position OFF does have any electrical function regarding power for accessories. Or do the electrics and accessories of the car only come alive when ignition is switched to RUN and ignition on?

Michael

 
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Hi guys,

I am just doing the adjustments on the ignition switch on my 71 Mach 1 and I would like to know if the position OFF does have any electrical function regarding power for accessories. Or do the electrics and accessories of the car only come alive when ignition is switched to RUN and ignition on?

Michael
Correct. Should also be able to run just the things like the radio and fan when you slip it backward into 'Accessories.'

 
The difference between ACC and RUN is that in RUN, power is added to the coil ignition wires and one particular fuse circuit that powers up door ajar signals, carb solenoids, emission controls, etc.

Interesting, when the key is in CRANK position, only those coil ignition wires and the one fused circuit are hot, along with the signal to crank the starter itself.

 
I was not aware the car has an ACC position. But now that you mention it... my Lincoln Mark IV has ACC on the ignition lock, so it is an obvoius conclusion the Mustang has it, too.

I will go to the garage an check...

Thanks for the help.

Michael

 
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I have tested it. The ignition lock cannot be turned backwards from the LOCK position. There is no ACC position switchable.

Everything else works, including the steering wheel lock.

I have changed the ignition lock cylinder with a new one some time ago. The whole mechanism behind it was cleaned and lubricated. Is it possible I reassembled it in a wrong way, so that ACC is gone? When I assembled it, I rather had the impression it only could be assembled in one way.

 
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Looking at the wiring diagram for your car

(http://www.7173mustangs.com/images/1971_full.pdf)

It does note that there should be an ACC position. You could confirm this by disconnecting the ignition cylinder linkage from the switch, and seeing if you could manually move the switch to the ACC position. This would let you know if the problem is your ignition cylinder, or the switch itself. Other than that, I don't know what much else you could try

 
ACC is in the counter clockwise position from OFF.

basically its ACC-OFF-RUN-START

ACC turns on everything but the coil.

Run is everything and coil.

start is starter and coil. Start is a momentary switch. so the second the engine kicks over you release and it springs back into RUN mode.

Now OFF, isn't exactly OFF. in OFF the brake lights, 4 way flashers and interior accessories are always on. The clock, the headlights switch, the door buzzer when the key is in the ignition all get power in OFF, but the more current draining items are off unless you select ACC or RUN.

 
I have found the problem.

I removed the new Scott Drake ignition lock cylinder and put in an old original Ford lock cylinder. Et voilà, it moves smoothly through the positions, including ACC.

A close inspection of the Drake cylinder shows that it is poorly made and when you put it in the LOCK position, it does not correctly line up with the detent marks of the mechanism. It is a few degrees out of tune.

This is enough to make the whole thing inoperable. I was not able to adjust the ignition switch and the inner gear assembly to work properly with the Drake part.

Does anyone have also experienced poor ignition lock fit or function with repro aftermarket locks? I think I will temporary use an old, good Ford cylinder and try to find a Ford NOS lock kit with all locks.

 
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