Ignition Switch
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Ignition Switch
Hello, does anyone have a wiring diagram for the ignition system on a 1970 F100?
My switch stuck on (spinning starter) and had to cut the battery cable, hope i saved the starter.
So I need a new ignition switch (Motorcraft SW944 -I Think)
If anyone has a better idea of how to run an ignition setup please let me know as I have the time to do the work now.
My switch stuck on (spinning starter) and had to cut the battery cable, hope i saved the starter.
So I need a new ignition switch (Motorcraft SW944 -I Think)
If anyone has a better idea of how to run an ignition setup please let me know as I have the time to do the work now.
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From: Simi Valley, CA
D1AZ11572C .. Ignition Switch KIT (Motorcraft SW1054) *
Fits: 1968/69 F100/750 & 1970 F100/750 before serial number G90,001.
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DOTZ11572A .. Ignition Switch (Motorcraft SW944)
Fits: 1970 F100/750 from serial number G90,001 / 1971/72 F100/750.
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* The D1AZ11572C ignition switch was a FoMoCo "campaign" replacement for C8AZ11572A ignition switch which shorted out and caught FIRE!
1968/69 Ford passenger cars also used this same C8AZ11572A switch.
Back then...there were no NHTSA (Federal Gov't) mandatory recalls to fix defective vehicles like there is today.
Ford sent out "campaign" letters to the dealers advising them of the problem. It was then up to the dealers to notify the owners of these vehicles that had the defective switch, not FoMoCo.
How many of these defective switches were replaced? Prolly most of them, but some were not.
The D1AZ switch also comes with a pigtailed wire plug. The plug fits to the switch, the wires were spliced into the wiring harness.
If anyone has one a these vehicles that uses this switch and the wires are not spliced in, the vehicle still has the ORIGINAL defective switch.
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From: Salt Lake City, UT
From the sound of what you are describing, it sounds more like the Starter Solenoid stuck and continued to power the starter. Starter solenoids are known to act this way after many years and hundreds of starts. Check the solenoid first before the actual key ignition switch. Unless the key remained in the start position when you turned it, it is probably not causing the problem. If the key switch operates right, (spring pushes it back to ON position when you let go of it), it probably is not defective. Check Starter Solenoid.
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The solenoid is brand new. I have had the starter 'die' twice in the last two months, I have just replaced everything in the line the solenoid, batt & starter pwr cables and starter this time. hooked it all up hopped in the truck turned the key and the starter would not quit turning the engine over eventhough it was running. I tried to turn the truck off using the key with no response. I then proceded to cut the battery cable between the battery and the solenoid.
I just figured the only not new part of the mix is the switch but perhaps i got a defective solenoid (spendy brass internal one)
I just figured the only not new part of the mix is the switch but perhaps i got a defective solenoid (spendy brass internal one)
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From: Salt Lake City, UT
The fact that the key wouldn't do anything makes it even more suspect that it is the solenoid. Once the solenoid sticks, the connection is permanently made between the battery and the starter motor. Under normal conditions, turning the key to off should cause the solenoid to be de-activated. It is possible it IS the Ignition switch. You can check that easy enough. Simply remove the small wire that attaches to the side of the solenoid. With the ignition switch in the off position or the on position, there shouldn't be any current to that wire. Check it with a multi-meter. With the Ignition switch in the start position, there should be power to that small wire. If it isn't working this way, then the Ignition Switch is bad. If it is working this way, then the Solenoid is bad.
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I seem to have a plug with all black wires on my current switch. So I believe i have the D1AZ style switch. I also believe it has been replaced since the plug has all black wires coming off it. two are dead ended (not hooked up).
I plan to go and get a new switch, will the Auto Zone have these or is this a Ford only part? should I replace it with a different style, should I go to a toggle switch and bush button for a starting setup? what would be the best way to proceded so i do not have to replace this agian in a few months. Prior to buying the truck the previous owner said he had the switch replaced ( checked my notes to confirm this).
forgot to mention the one I removed has the blade style prongs that mate to the plug
thank you
Jim
I plan to go and get a new switch, will the Auto Zone have these or is this a Ford only part? should I replace it with a different style, should I go to a toggle switch and bush button for a starting setup? what would be the best way to proceded so i do not have to replace this agian in a few months. Prior to buying the truck the previous owner said he had the switch replaced ( checked my notes to confirm this).
forgot to mention the one I removed has the blade style prongs that mate to the plug
thank you
Jim
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From: Kernersville, NC
I'm in agreement with everyone else.
It's probably the solenoid, and NOT the ignition switch.
Have you checked the solenoid using MotorDog's method? If not, you need to do that before spending the money for a switch only to find out that's not the culprit.
Troubleshooting is the first step in repairing something. Don't just throw parts at it like they do at dealerships nowadays.
CHECK THE SOLENOID!!!
It's probably the solenoid, and NOT the ignition switch.
Have you checked the solenoid using MotorDog's method? If not, you need to do that before spending the money for a switch only to find out that's not the culprit.
Troubleshooting is the first step in repairing something. Don't just throw parts at it like they do at dealerships nowadays.
CHECK THE SOLENOID!!!
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The solenoid was brand new when i turned the key when all this happened. I did check to see if pwr was at the (S) connections with the starter lead disconnected and I had 12.5v at that connections I also did not have any voltage on the starter cable side of the solenoid... I plan to replace both because this is the 3rd time I have replaced the solenoid and starter in the last 2 months, the only thing not replaced was the switch.
Thank you.
Thank you.
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The solenoid is grounded to a lead wire from the neg terminal on the battery directly to the mounting bolt for the solenoid. is this wrong?
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From: Kernersville, NC
If all of those components have been recently replaced, there's a VERY GOOD probability that you've got wiring problems.
Those can be intermittent and can be very hard to diagnose.
If you haven't tried a new switch yet, go ahead and get one for it. That's apparently the only thing you haven't replaced, and that's a cheap, easy fix compared to tracing down a wiring problem unless you've had a lot of experience with electrical systems.
Those can be intermittent and can be very hard to diagnose.
If you haven't tried a new switch yet, go ahead and get one for it. That's apparently the only thing you haven't replaced, and that's a cheap, easy fix compared to tracing down a wiring problem unless you've had a lot of experience with electrical systems.
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I have been looking for a wiring diagram to follow so I can replace 'all' the wiring associated with the ignition system when I replace the switch. This is so I know it was done correctly and by me not some guy who does not care if it fails a few weeks later.
I found a diagram (Master) on FORDidentification but I would like to find a more detailed one with perhaps the switch only on it.. any ideas of a place look?
I would like to thank everyone for their information as it has all added in my diagnosis and course of repair.
thanks again.
I found a diagram (Master) on FORDidentification but I would like to find a more detailed one with perhaps the switch only on it.. any ideas of a place look?
I would like to thank everyone for their information as it has all added in my diagnosis and course of repair.
thanks again.
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From: Butler, IN
You mentioned a site to that you found a wiring diagram. It is a good diagram but confusing due to it not being color coded. You may have to buy a color coded diagram. But the switch only has 7 wires coming off it so it shouldn't be hard to trace.
Good luck!! Because wiring problems are one of the hardest to diagnose and repair.