Does the mustang have a wire that is hot key-on AND start? Wiring ignition sys.

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
43
Arlington, MA
When last I wired and looked for it, I could not find one. Since I only had key-on hot, I had to wire the ignition system directly to the battery with a switch inbetwen. This amuses my friends cause I can take the key out while the car is moving and engine still runs but it is kind of ghetto and I seek to return to the fold of regularity.

I have a nice duraspark ii box and stock coil to replace the crane hi-6s and ls-92 coil. hen I can make a few bucks and make the car's powertrian all ford.

So is there such a wire in the car?
 
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superhuaman

New Member
Nov 8, 2004
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Harrisburg, PA
ummm...i assume youre not using the factory dash wiring? cuz the wire you want is right there, in the plug that goes between the factory dash harness and the factory engine harness. i will elaborate...

at the ignition switch, the red with light green wire (R/LG) is hot in run. the brown with pink wire (BR/PK) is hot in start. somewhere in the dash harness, they are spliced together.

after the splice, there is a 20 gauge fuse link, and the R/LG wire proceeds on, to connector number 110 (C110) in the "RH rear engine compartment".

how does this help you? well...if you still have the brown plug over by the brake booster, that is C110. and if you take the red wire with light green stripe, it should run your ignition. test with a light or meter first though, and make sure it has power in start and run, and no other time. :D
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
43
Arlington, MA
No I'm not using the factory wiring....all that is left of the factory wiring is the ignition switch, wiper wires, lights wiring and the guages wiring. I cut out everything not required to clean it up.

There must be something special about the splice. If I just merge the 2 wires, then the power will go over the splice and run the starter whenever I key-on so that wont work. Is there a relay or resistor in there?
 

superhuaman

New Member
Nov 8, 2004
907
0
0
Harrisburg, PA
There must be something special about the splice. If I just merge the 2 wires, then the power will go over the splice and run the starter whenever I key-on so that wont work. Is there a relay or resistor in there?

No, thats not true. the white with pink wire (W/P) is the one that goes to the starter solenoid. it normally goes to the ignition too, but remember, the factory tfi ignition module has separate Start and Run terminals.

remember, the ignition switch has 5 different switches in one. theres 4 different wires that come off Start, 4 off Run, and 1 off Acc.
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
43
Arlington, MA
Allright, I'll try splicing together the r/lg with the br/pk and see if the car starts starting.

Does the white/pk come from a different plug on the column? Is it seperate from the br/pk wire?
 

jrichker

StangNet's favorite TOOL
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Mar 10, 2000
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lowendmac.com
Diagram courtesy of Tmoss & Stang&2birds
IgnitionSwitchWiring.gif


TMoss & Stang&2birds site is your best friend. Save it in your Favorties...

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer, actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
 

crazypete

All my crevices are greased.
Oct 22, 2004
930
4
18
43
Arlington, MA
So I was right....there IS no hot key on and run wire. It is created from splicing the brown/pink (start hot) with red/green (run hot).

I did my splice and all is good. I find it kind of odd the factory did not just simply produce a dual hot wire rather than splicing. The whole splice thing seems like a duct tape solution.

oh well! Ignition system, here I come!​
 

jrichker

StangNet's favorite TOOL
SN Certified Technician
Mar 10, 2000
27,397
2,732
234
75
Dublin GA
lowendmac.com
So I was right....there IS no hot key on and run wire. It is created from splicing the brown/pink (start hot) with red/green (run hot).

I did my splice and all is good. I find it kind of odd the factory did not just simply produce a dual hot wire rather than splicing. The whole splice thing seems like a duct tape solution.

oh well! Ignition system, here I come!​

It was probably done that way due to the limitations on the size and position of the contacts inside the switch. Sometimes it is easier to make more contacts than it is to make bigger contacts or contacts that span two functions like Run and Start.