Ignition switch for 1970 Ford 4000

K Dog

New User
I'm replacing the ignition switch on my 1970 Ford 4000 (3 cylinder, gas engine) with a new, but general switch that has different terminology when compared to the manual and the old switch. I need help determining which terminal each wire is supposed to connected to. Attached is a photo of the switch. At the 6 o'clock position is terminal #1 which has a normal sized terminal and a wide terminal. The next terminal moving in the counter clockwise direction is #5 (4 o'clock), and then #2 (2 o'clock), then #3 (11 o'clock), and then #4 (8 o'clock) which has 2 normal size terminals.

The 5 wires go the following locations:
-Brown wire to the voltage regulator
-Brown and red wire to the ignition coil
-White wire with a 3 amp fuse eventually gets to the front of the block
-Brown wire to the light switch
-White wire goes to the plug that leads to the voltage regulator

Thanks for any help.

mvphoto26282.jpg
 
(quoted from post at 09:53:39 08/19/15) I'm replacing the ignition switch on my 1970 Ford 4000 (3 cylinder, gas engine) with a new, but general switch that has different terminology when compared to the manual and the old switch. I need help determining which terminal each wire is supposed to connected to. Attached is a photo of the switch. At the 6 o'clock position is terminal #1 which has a normal sized terminal and a wide terminal. The next terminal moving in the counter clockwise direction is #5 (4 o'clock), and then #2 (2 o'clock), then #3 (11 o'clock), and then #4 (8 o'clock) which has 2 normal size terminals.

The 5 wires go the following locations:
-Brown wire to the voltage regulator
-Brown and red wire to the ignition coil
-White wire with a 3 amp fuse eventually gets to the front of the block
-Brown wire to the light switch
-White wire goes to the plug that leads to the voltage regulator

Thanks for any help.

mvphoto26282.jpg
ou know that one terminal (likely #3) goes to start safety sw & to solenoid beyond that, yet, you make no mention of that in your wire list???? I think you need better info of where other end of all wires connect (front of block isn't good enough). The terminal with two spades will be power into sw & lighting out.
 
You say:

I'm replacing the ignition switch on my 1970 Ford 4000 (3 cylinder, gas engine) with a new, but general switch that has different terminology when compared to the manual and the old switch.

But you don't provide us what the "different terminology" is. If you could provide us the descriptions or names of the numbered terminals on the new switch according to the paperwork that came with it, we would be better able to help you determine how to hook up your existing wires to it.
 
also, to add to confusion, most replacement switches will fit gas or diesel--prob. have a terminal for diesel cold start that you don't need. hook up to 12v & test light will knock down the choices.
 
(quoted from post at 09:53:39 08/19/15) I'm replacing the ignition switch on my 1970 Ford 4000 (3 cylinder, gas engine) with a new, but general switch that has different terminology when compared to the manual and the old switch. I need help determining which terminal each wire is supposed to connected to. Attached is a photo of the switch. At the 6 o'clock position is terminal #1 which has a normal sized terminal and a wide terminal. The next terminal moving in the counter clockwise direction is #5 (4 o'clock), and then #2 (2 o'clock), then #3 (11 o'clock), and then #4 (8 o'clock) which has 2 normal size terminals.

The 5 wires go the following locations:
-Brown wire to the voltage regulator [b:d73cc7389a]SW #1 (wide)[/b:d73cc7389a]
-Brown and red wire to the ignition coil [b:d73cc7389a]sw #4[/b:d73cc7389a]
-White wire with a 3 amp fuse eventually gets to the front of the block [b:d73cc7389a]on old sw this was on same terminal as ign coil[/b:d73cc7389a], [b:d73cc7389a]on new it will be fine on same as ign coil OR you can connect to sw #2[/b:d73cc7389a]
-Brown wire to the light switch [b:d73cc7389a]sw #1 (narrow)[/b:d73cc7389a]
-White wire goes to the plug that leads to the voltage regulator [b:d73cc7389a]likely error here. I believe this is wht/yel wire going to neutral safety start sw & would connect to SW #3
Sw #5 is un-used [/b:d73cc7389a]

Thanks for any help.

mvphoto26282.jpg
b:d73cc7389a][/b:d73cc7389a]
 
(quoted from post at 11:44:26 08/19/15)
(quoted from post at 09:53:39 08/19/15) I'm replacing the ignition switch on my 1970 Ford 4000 (3 cylinder, gas engine) with a new, but general switch that has different terminology when compared to the manual and the old switch. I need help determining which terminal each wire is supposed to connected to. Attached is a photo of the switch. At the 6 o'clock position is terminal #1 which has a normal sized terminal and a wide terminal. The next terminal moving in the counter clockwise direction is #5 (4 o'clock), and then #2 (2 o'clock), then #3 (11 o'clock), and then #4 (8 o'clock) which has 2 normal size terminals.

The 5 wires go the following locations:
-Brown wire to the voltage regulator [b:4d423c9984]SW #1 (wide)[/b:4d423c9984]
-Brown and red wire to the ignition coil [b:4d423c9984]sw #4[/b:4d423c9984]
-White wire with a 3 amp fuse eventually gets to the front of the block [b:4d423c9984]on old sw this was on same terminal as ign coil[/b:4d423c9984], [b:4d423c9984]on new it will be fine on same as ign coil OR you can connect to sw #2[/b:4d423c9984]
-Brown wire to the light switch [b:4d423c9984]sw #1 (narrow)[/b:4d423c9984]
-White wire goes to the plug that leads to the voltage regulator [b:4d423c9984]likely error here. I believe this is wht/yel wire going to neutral safety start sw & would connect to SW #3
Sw #5 is un-used [/b:4d423c9984]

Thanks for any help.

mvphoto26282.jpg
b:4d423c9984][/b:4d423c9984]



Thanks for the help. The wire that appears to end up at the front of the block is difficult to follow from the switch under the dash and past the voltage regulator since the wires have been wrapped in tape by the previous owner.
 

The different terminology refers to the terminology on the old switch. The white wire and a brown wire plugged into a terminal labeled ACC. The white/yellow wire plugged into a terminal labeled BAT. The brown and the brown/red wires plugged into two terminals labeled IGN.

The box with the new switch did not have a diagram.

Thanks.
 
Sounds like the old switch was not the original one, as the original switch had numbered terminals like your replacement.


Just an FYI - The white wire with the 3 amp fuse should go to the voltage stabilizer on the back of the instrument cluster, not to the front of the engine. If you had difficulty tracing the wire and just found a white wire at the front of the engine then you might have found a different wire that just happens to also be white.
 
(quoted from post at 15:43:34 08/19/15)
The different terminology refers to the terminology on the old switch. The white wire and a brown wire plugged into a terminal labeled ACC. The white/yellow wire plugged into a terminal labeled BAT. The brown and the brown/red wires plugged into two terminals labeled IGN.

The box with the new switch did not have a diagram.

Thanks.
here did this "white/yellow" come from? There was no mention of it in your original post???
Did it all work, at anytime, with the old switch?
 
(quoted from post at 13:52:29 08/19/15)
(quoted from post at 15:43:34 08/19/15)
The different terminology refers to the terminology on the old switch. The white wire and a brown wire plugged into a terminal labeled ACC. The white/yellow wire plugged into a terminal labeled BAT. The brown and the brown/red wires plugged into two terminals labeled IGN.

The box with the new switch did not have a diagram.

Thanks.
here did this "white/yellow" come from? There was no mention of it in your original post???
Did it all work, at anytime, with the old switch?

Sorry for the confusion, I'm new at this and trying to learn and have made a few mistakes. I just retraced the 5 wires and found the below:
- the white goes to the 3 amp fuse and I have voltage through the fuse
- the white/yellow (I forgot to add yellow in original post) turns into a white/red through a splice and then goes to a plug which goes to the voltage regulator
- the brown/red goes to the ignition coil
- the brown to the light switch
- a second brown to the voltage regulator

Tractor History (you may be sorry you asked): I've had it 3 years and it has ran great. The battery died a month ago and in the process of charging it and then using the tractor without issues, the tractor stopped running. I got a new battery (the 17TF model that is supposed to be in the 1970 Ford 4000) and it would turn over but would not start. I replaced the distributor cap, dust cover, ignition coil, and cleaned the point and it fired off but would not stop when I turned the key off. So, I'm now replacing the switch.

Thanks again for your help educating me on my tractor.
 
According to the wiring diagram, there should only be one wire going from the key switch to the Voltage Regulator, and that one was originally a Brown wire and it goes to the "B" terminal on the VR, and a second brown wire goes from that same "B" terminal to the large post on the starter relay that's also connected to the hot side of the battery. Are you sure that the white/yellow wire that's spliced to the whit/red wire continues on to the VR? If so, what terminals on the VR do the two wires (brown & white/red) connect to on your tractor, and which color wire to which VR terminal?

The white/yellow wire originally went to the safety starter switch in the transmission and the other side of the safety switch went to the primary of the starter relay via a white/red wire, so the fact that the white/yellow wire is spliced to a white/red wire sounds like a previous owner might have bypassed the safety switch in the transmission.
 
(quoted from post at 18:12:31 08/19/15) According to the wiring diagram, there should only be one wire going from the key switch to the Voltage Regulator, and that one was originally a Brown wire and it goes to the "B" terminal on the VR, and a second brown wire goes from that same "B" terminal to the large post on the starter relay that's also connected to the hot side of the battery. Are you sure that the white/yellow wire that's spliced to the whit/red wire continues on to the VR? If so, what terminals on the VR do the two wires (brown & white/red) connect to on your tractor, and which color wire to which VR terminal?

The white/yellow wire originally went to the safety starter switch in the transmission and the other side of the safety switch went to the primary of the starter relay via a white/red wire, so the fact that the white/yellow wire is spliced to a white/red wire sounds like a previous owner might have bypassed the safety switch in the transmission.

The white/red wire goes into the plug pictured below and the the wires on the other end of the plug go into the VR.
mvphoto26310.jpg
 
I found where the white/red wire splits with a cluster of wires (see photo) and bypasses the VR. The only wires to go to the VR are the brown, blue, yellow/black, and black (see photo). Sorry about the mistake from previous post.
mvphoto26313.jpg


mvphoto26314.jpg


img
 
The original key switch for a 3 cylinder gasser had 3 numbered terminals. Terminal number 1 had two spade connectors, one larger than the other. Terminal 2 also had two spade connectors, but they were both the same size. Terminal 3 only had one spade connector.

Here are the original color wires that were hooked to the key switch from the factory and what they went to and which key switch terminal they were originally connected to:

Terminal 1 (Hot terminal):
Brown wire was originally connected to the large spade connector of original key switch terminal number 1 went to Terminal "B" of the voltage regulator. The "B" terminal of the VR was also connected to the Starter relay via another brown wire and on to the hot side of the battery by the large battery cable that was connected to the same post on the starter relay, so the number 1 terminal of the original key switch was always hot.

Brown wire on the small spade connector on key switch terminal number 1 originally went to the light switch. The light switch was therefore also always hot.

Terminal 2 (Run position of key switch):
White wire was connected to one of the spades on terminal 2 went to the 3 amp fuse and on to the voltage stabilizer on the back of the instrument cluster.

Brown wire with red stripe was connected to the other spade on terminal 2 and was connected to the primary of the coil. This length of wire originally had a thick section in it that looked similar to a fusible link, but was in fact a "resistance wire" that provided the external resistance for the coil as the original coil required an external resistor.

Terminal 3 (Start position of key switch):
White wire with yellow stripe originally went to the starter safety switch in the transmission and a white wire with red stripe went on from the safety switch to the primary on the starter relay. The starter safety switch would only allow the starter to engage if the transmission was in neutral on a manual transmission tractor or in Park on a Select-O-Speed transmission tractor.

Since your new switch came with no documentation you need to use an ohm meter to see which terminals on your new switch have continuity to which other terminals with the key in the various positions. Once you have determined that you should be able to figure out which terminal is supposed to always be hot, and that would correlate to the original key switch terminal 1. You should also be able to determine which terminal has continuity to the "always hot" terminal when the key is in the "Run" position, and that one would correspond to the original terminal 2. You should also be able to determine which terminal only has continuity to the "always hot" terminal when the key is in the "Start" position and that would correlate to the original terminal 3.
 

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