Ignition Switch Wiring

[drewsky121]

if your wanting to run the fan between runs or an electric water pump put those on a separate relay and switch. I can show you how to use a diode to isolate that relay so it will power up with the regular accessory switch, but then not power up all the accessories when you just want to run the fan.

yea i appreciate it, i run my fan on my 89 from a relay, but i'm not planning on running an electric water pump on either car. heard its not ideal for road race cars. but i appreciate any input.

So, mcglsr2, based on what i've looked at... i'm going to be running Relay 1, 3, 5, and 7. None of my sensors are hooked up for low oil or brake fluid... i do not have ac or heat, and i don't need the accessories function.

So I need 4 relays, and three switches.

1 switch for "Run" which would be relay 7 that includes the ignition system and control module, 1 momentary switch for "Start" which ties into the starter (relay 1), and 1 for the accessories for wipers/radio/ac, since my autometer gauges are wired using the radio wires and i can tie in my O2 sensors as well in that switch, so relays 3 and 5.

Am i correct? does this sound accurate?

I do apologize for the confusion.. i'm trying to start the car up for the first time this weekend, so i'm trying to make sure i have my head wrapped around this properly so i don't screw something up royally.

 

[mcglsr2]

yea i appreciate it, i run my fan on my 89 from a relay, but i'm not planning on running an electric water pump on either car. heard its not ideal for road race cars. but i appreciate any input.

So, mcglsr2, based on what i've looked at... i'm going to be running Relay 1, 3, 5, and 7. None of my sensors are hooked up for low oil or brake fluid... i do not have ac or heat, and i don't need the accessories function.

So I need 4 relays, and three switches.

1 switch for "Run" which would be relay 7 that includes the ignition system and control module, 1 momentary switch for "Start" which ties into the starter (relay 1), and 1 for the accessories for wipers/radio/ac, since my autometer gauges are wired using the radio wires and i can tie in my O2 sensors as well in that switch, so relays 3 and 5.

Am i correct? does this sound accurate?

I do apologize for the confusion.. i'm trying to start the car up for the first time this weekend, so i'm trying to make sure i have my head wrapped around this properly so i don't screw something up royally.

Sorry I didn't get a chance to post last night, I got in pretty late and had to get up for work in the morning. I'll update more tonight, and I'll take a look at the relay's you mentioned. Also, I think you can get away with just 1 switch - a OFF - ON - MOMENTARY one. I'm pretty sure these exist, let me do a little research. I'll post up later tonight when I get home from work.

 

[drewsky121]

Sorry I didn't get a chance to post last night, I got in pretty late and had to get up for work in the morning. I'll update more tonight, and I'll take a look at the relay's you mentioned. Also, I think you can get away with just 1 switch - a OFF - ON - MOMENTARY one. I'm pretty sure these exist, let me do a little research. I'll post up later tonight when I get home from work.

no reason to apologize, you're helping me out! and i appreciate it greatly. i have found several On-Off-On switches, haven't been able to find a momentary one, but i still would think that i would want at least two switches so i can turn everything off except for the ignition so i'm not draining the battery while turning over the starer.

 

[ttocs]

http://www.jegs.com/webapp/wcs/stor...ear=&make=&model=&submodel=&engine=&Nrpp=&No=

I did a search for off run start switches. This is the first that came up. You might be able to find cheaper and I am not necessarily saying that is a good thing. Don't cheap out on these switches too much as they are CRITICAL to the system. Also what kind of connections are you usuing? I would recomend nothing less then solder.

 

[drewsky121]

Also what kind of connections are you usuing? I would recomend nothing less then solder.

absolutely! I solder everything, and definitely will be doing the same for this. Thanks for the help in this process!

 

[mcglsr2]

no reason to apologize, you're helping me out! and i appreciate it greatly. i have found several On-Off-On switches, haven't been able to find a momentary one, but i still would think that i would want at least two switches so i can turn everything off except for the ignition so i'm not draining the battery while turning over the starer.

No much action from me over the weekend, I ended up not being home much.

This is the type of switch you want: here. You shouldn't have too much trouble finding switches, google for "OFF-ON-MOMENTARY switch."

And honestly, you don't two physical switches - the OFF-ON-MOMENTARY acts as two switches. The down position is OFF, meaning the car is completely off. The middle position is ON, or in our case, RUN. The up position is START - and it won't stay in the up position. That's the momentary part. Basically you work the switch like this: it starts in the bottom/OFF position. You flip it up to the middle/ON (RUN) position. You car is now "on." You press and hold it in the up/MOMENTARY (START) position until the car starts, then release it. The switch will then fall back into the middle/RUN position, which is what you want. When you want to turn off the car, simply move the switch down to the OFF position.

I'll work on the diagram tonight, to reflect what ttocs said about just energizing stuff for the START.

EDIT: Oh, a note about about these switches - the one I linked was rated at 20 Amp. That's good, but not enough as the circuits have 40 Amp fuses. But, good news, it doesn't matter - that's why we are using relays. The relays bear the brunt of the amperage draw, not the switch. The switch needs enough to just energize the relay coil. You could get away with a 5 Amp switch (and probably less). So 20 Amp, in this case, is overkill (but still feel free to use it, it won't hurt). If you were running just switches and no relays, then your switches will need to be rated at like 40 Amp. Which is quite a heavy duty switch (and probably expensive).

 

[mcglsr2]

Okay, updated diagram:

This shows a couple things:

1. You only need 1 switch to control the whole car. This switch is an OFF-ON-MOMENTARY ON switch. I described how it will work in a previous post. If I'm not mistaken (I don't have one to test with) there will be 3 terminals on this switch. One terminal will be common to the other two, meaning two positions will share this one terminal. This terminal should go to a good chassis ground. The other two terminals will be used for the ON (RUN) and MOMENTARY ON (START) positions. A wire will go from the appropriate terminal to the appropriate relays.
2. You said you only care about relays 1, 3, 5 & 7. So, the ON (RUN) terminal will go to relays 3, 5 & 7. The MOMENTARY ON (START) will go to relays 1 & 7.
3. Relay 7 will be energized during both the START and RUN functions. The wiring for this relay is shown in the diagram above.
4. In previous diagrams, I had shown the relay getting power from the circuit input - we shouldn't do this as the circuits could be carrying a lot of amperage. I updated the wiring diagram to how how the relay coil should be energized - a separate feed from the battery. This +12v BATT source can be shared by all relays, meaning the one source can split to go to each relay. The switch will then control the ground (and thus whether the relay is on or not). By doing this, we know that the +12V BATT feed (and thus coil) won't see much in the way of amperage. Make sure this +12V BATT feed is fused near the battery, the amp draw should be quite low. I imagine a 5amp fuse would be more than enough.

The above will only energize the STARTing circuits when starting the car, and then energize the RUN curcuits after the car has started. You can put the car in RUN without starting it. And to turn the car off, just flip the switch off, which will remove power from all relays.

Let me know if you have any questions!

 

[drewsky121]

Okay, updated diagram:

This shows a couple things:

1. You only need 1 switch to control the whole car. This switch is an OFF-ON-MOMENTARY ON switch. I described how it will work in a previous post. If I'm not mistaken (I don't have one to test with) there will be 3 terminals on this switch. One terminal will be common to the other two, meaning two positions will share this one terminal. This terminal should go to a good chassis ground. The other two terminals will be used for the ON (RUN) and MOMENTARY ON (START) positions. A wire will go from the appropriate terminal to the appropriate relays.
2. You said you only care about relays 1, 3, 5 & 7. So, the ON (RUN) terminal will go to relays 3, 5 & 7. The MOMENTARY ON (START) will go to relays 1 & 7.
3. Relay 7 will be energized during both the START and RUN functions. The wiring for this relay is shown in the diagram above.
4. In previous diagrams, I had shown the relay getting power from the circuit input - we shouldn't do this as the circuits could be carrying a lot of amperage. I updated the wiring diagram to how how the relay coil should be energized - a separate feed from the battery. This +12v BATT source can be shared by all relays, meaning the one source can split to go to each relay. The switch will then control the ground (and thus whether the relay is on or not). By doing this, we know that the +12V BATT feed (and thus coil) won't see much in the way of amperage. Make sure this +12V BATT feed is fused near the battery, the amp draw should be quite low. I imagine a 5amp fuse would be more than enough.

The above will only energize the STARTing circuits when starting the car, and then energize the RUN curcuits after the car has started. You can put the car in RUN without starting it. And to turn the car off, just flip the switch off, which will remove power from all relays.

Let me know if you have any questions!

This was genius, and very well though out. Thank you! When i was talking about the previous two switches, i was referencing having one solely dedicated just for the accessories so i can switch them off, but it does make more sense to just wire it up to one switch. Thank you very much for taking the time to figure this out for me. I'll be taking care of it all as soon as i get the chance. Very much appreciated!

Andrew

 

[mcglsr2]

This was genius, and very well though out. Thank you! When i was talking about the previous two switches, i was referencing having one solely dedicated just for the accessories so i can switch them off, but it does make more sense to just wire it up to one switch. Thank you very much for taking the time to figure this out for me. I'll be taking care of it all as soon as i get the chance. Very much appreciated!

Andrew

Sure thing! Let me know how it goes!

And if you do decide to run an Accessory, you can if you want to. In that case, you will use a second switch, a normal one: OFF-ON. And then wire it in the same fashion to the relays it would need. The only "gotcha" there would be to ensure that the ACC switch is off when you intend to START and RUN the car. If you decide you want this, let me know, I'll put a little more thought into it and see if we can come up with a way that putting the car in RUN/START would automatically shut off the ACC switch if it were on.

 

[ttocs]

I thought you had mentioned at one point you wanted a switch to keep the fan running between runs? You can add a switch for it and diode isolate it(super easy) so that it would not power any of the other accesories when that switch is on.

 

[Anthony Todd Storey]

I know this is a old post but I have a question.
I’ve got a 95 mustang gt I’m planning a swap with the drive line wiring. Problem I’m having is I can’t find any information on how to take the wires off the 95 ignition switch and rewire them to an old style key switch that mounts in the dashboard like a 65 mustang has. The 95 has a lot of wires the 65 doesn’t LOL

 

[ttocs]

I think the only difference is an extra accessory wire or two. That is not a big deal to add extra accessory wires off of the existing one with a relay or two.

 

[Anthony Todd Storey]

The 65 switch operate simply by turning the key
the 95 key pulls a rod so not sure where to put the wires so I do not fry the computer with this swap

 

[Anthony Todd Storey]

From this 1995 switch to this 1965 switch his

 

[ttocs]

its all about the wiring. Can you get a schematic of the 65?

 

[Anthony Todd Storey]

Yes I have that. I know being there is more wires I will probably have to double up on some of the connections

 

[ttocs]

I still am really not sure why you need the 65 ignition in the car myself?

 

[Anthony Todd Storey]

Because I’m swapping the 95 drive line and harness to the 65
the steering column in the 65 doesn’t have the key switch in it. It’s on the dash

 

[ttocs]

I see said the blind man. If you can get a good pic or link to the 65 schematic I have the 95 wiring manual. Do you know the difference between a true ignition and an accessory wire? An ignition will stay powered while the motor is cranking so a true ignition was to power the ecu for example. I Am not sure the 65 will have a true ignition though since it was carb but find out what the outputs are on that switch and we can go from there

 

[Anthony Todd Storey]