70 ignition switch assembly

['70MACH1 10]

I think I have a problem with my ignition switch. When I put a test light to the key switch side of the coil the light is dim. After I turn the key switch a couple of times it gets bright. Could it be the actual key switch and not the assembly? I've checked the plug and it appears to be ok. I've looked on line and there is no switch available for '70, but it looks like the one for the '71-'73. Any thoughts:001_unsure:

[magician 13]

You really need a meter to read the true voltage. Check it at the column side of the plug and see if u get the same thing. Do you have factory coil and ignition set up?

['70MACH1 10]

No it's a msd blaster 2 coil.

[70Mach03 12]

The 71 is not the same although it looks similar. Mine went out a few years back and I chased them on e-bay up to around $200 before dropping out. Finely found a complete 1970 steering column at Carlisle for $50. I then asked the vendor if I could borrow a wrench to remove just the switch. He said, "If that's all you want I got a whole box of them over here." He then brought over a cardboard box that had about a dozen in it for $10 each. I bought two. When I got back home, I took out some electronic tuner cleaner and cleaned up both of them good plus my original switch. I got them so clean, I wasn't sure which was my original. However, whichever one I picked and put back in worked great.

 

You might want to try that with your original switch. Spray it real good and work the mechanism back and forth. It may work for you.

['70MACH1 10]

I'll try the cleaner. Thanks:yes:

['70MACH1 10]

The cleaner didn't work..

[Big Secz 26]

The '70 ignition switch is a one year/one model part that is not reproduced. The closest match is a '69, I went through this before for someone a couple years ago and I think there are only two wires that are a different color between the '69 and the '70 switches and the pig tail on the '69 switch is shorter. In theory you can buy a '69 switch and cut the plug off of the '70 switch and splice it on the '69 switch by matching up the correct wires and giving you the correct length.

[Rsanter 152]

I have a spare 70 collumn I can see if it has a switch in it

 

Bob

[miketyler 15]

How are you testing the switch? Though less likely, could be wiring or connection issue.

[Big Secz 26]

I think I know what your issues is now that I look at it more. You have an MSD coil which requires 12 volts constant. I think you have a resistor wire coming from the ignition which is preventing you from getting the constant 12 volts you need. Run another power lead from a switched source that gives you the 12 volts.

['70MACH1 10]

I finally found a brand new through Autozone for only $24. If you read the info on their web site it tells what the switch does. It pretty much nails the problem I've had off and on with the car.Thanks for all the help.

[Big Secz 26]

I don't think that's the right switch. Looks like a '71.

 

http://www.autozone.com/autozone/parts/Duralast-Ignition-Switch/1970-Ford-Mustang/_/N-iqksyZ9rigt?itemIdentifier=122317_0_0_

 

Here's a '70

http://forums.mustangandfords.com/mustang-monthly/70/6425837/the-general-discussion/70-mustang-ignition-switch-assembly/

http://www2.cougarpartscatalog.com/d0az-11572-a.html

 

Mustangs Unlimited has one for sale. I would call them to confirm before ordering.

http://www.mustangsunlimited.com/itemdy00.asp?T1=SW882%2001

 

The plugs are different and the length of the wires on a '70 is much longer because it is mounted higher up on the steering column than '71 cars.

[Big Secz 26]

Ok...I pulled out my '70 and '71 shop manuals. The switch from Autozone, if that is the same switch as in the picture is definitely a '71

 

You can use the plunger portion of it but you will need to cut the pigtail and plug off of your '70 switch and solder it to the '71 switch. If you want to go that route here are the wire colors and identification for each switch.

 

'70:

Red/White Stripe - (P) Proof No. 1

Yellow - (B) Battery

Pink - (I) Ignition

Red/Blue Stripe - (S) Start

Black/Green Stripe - (A) Accessory

Violet - (P) Proof No. 2

Black - (G) Ground

 

'71:

Red/White Stripe - (P) Proof No. 1

Yellow - (B) Battery

Red/Light Green Stripe - (I) Ignition

Red/Light Blue Stripe - (S) Start

Black/Green Hash - (A) Accessory

Purple/White Stripe - (P) Proof No. 2

Black - (G) Ground

[Midlife 814]

The purple wire powers the brake master cylinder centering switch; it is not a proof-out circuit.

 

The red/white wire is occasionally used for the proof-out circuit for the oil pressure lamp; it definitely is not used in 70 nor 1971 Mustangs, but is used on other vehicles.

 

For 1970 the pink resistor wire goes from the fuse box to the gauge plug in the engine compartment (standard dash) or from the tach plug (tach dash). The wire going to the ignition is green/red or red/green.

 

These aftermarket ignition switches are generic switches, not Mustang specific. They will work, however.

[Big Secz 26]

The purple wire powers the brake master cylinder centering switch; it is not a proof-out circuit.

 

The red/white wire is occasionally used for the proof-out circuit for the oil pressure lamp; it definitely is not used in 70 nor 1971 Mustangs, but is used on other vehicles.

 

For 1970 the pink resistor wire goes from the fuse box to the gauge plug in the engine compartment (standard dash) or from the tach plug (tach dash). The wire going to the ignition is green/red or red/green.

 

These aftermarket ignition switches are generic switches, not Mustang specific. They will work, however.

 

 

So you are saying the '70 and '71 shop manuals are wrong?.....Interesting.

[Midlife 814]

I looked briefly through the 70 shop manual and couldn't find anything on the ignition switch (probably didn't look hard enough), but remember, these shop manuals covered all makes and models from Blue Oval.

 

Ahhh...found it Pg 33-02-06. Yes, that description is a general description for all makes/models.

[Big Secz 26]

Ok...I pulled out the 'ol Haynes book. Midlife can help fill in some blanks or clarify....

 

'70

Red/Green Stripe - Runs to a connector for tach and meets Pink wire for ignition

Yellow - Battery

Red/Blue Stripe - Neutral Safety Switch

Black/Green Stripe - Brake warning light

Violet - Brake switch

Black - Ground

 

'71

Lt Green/Red Stripe - Alt. Regulator

Yellow - Battery

Red/Lt. Green Stripe - Ignition (from fuse panel)

Red/Lt. Blue Stripe - Neutral Safety Switch

Black/Green Has - Fuse panel (splice with wipers)

Purple/White Stripe - Brake Switch and warning light

Black - Ground

 

 

In other words save yourself the headache and get an original '70 Mustang ignition switch and be done with it.

[Midlife 814]

Black/green is the ACC output to all ACC systems; it is converted to ACC from BATT by the ignition switch.

 

green/red or red/green is the primary wire that goes from the ignition to the coil, sometimes via a tach.

['70MACH1 10]

Well I should have the switch by tuesday and I will you guy's know. It wouldn't be the first time the manual was wrong on the wiring. The color code for the three wire plug that goes to the coil and oil gauge on my 70 has the color code for a 69....just sayin'

Edited April 28, 2014 by '70MACH1

['70MACH1 10]

[ATTACH]17023[/ATTACH]

 

[ATTACH]17024[/ATTACH]Big Secz and Midlife I appreciate all the input. I got the switch in the mail and the pigtail was to short and the plug was different. The wire configuration was the same except the pink wire was red w/green stipe the purple was purple with white strip. It looked pretty much the same, so I cut and soldered the old plug to have enough length. It didn't change anything except the car won't start. In theory it should have worked. I'll be double checking it in the morning.:taz:

[Midlife 814]

Wrong plug coming from the turn signal switch.

[Big Secz 26]

I knew it would be the wrong one. The one you got is for a '71 and up, and like I said the plug would not be correct and the wires would be too short.

[Kris 90]

Seems like it should be an easy swap if the only problem is the wires being short. If the switch is correct, you should be able to solder the harness from the old one to the new one like you said you have done. Make sure that you don't just switch it over by matching wire color. You need to make sure that the wire color you are matching up goes to the same pin location on the old plug. This would be my guess as to why it doesn't work now that you switch it. I bet even though the wire colors on some of them were the same between the two switches, some of the wires did not go the the same pin location on each plug. It could also be a bad solder joint also. That should be easy to check. If you ohm the connector on the switch or whatever you soldered to, (not the solder itself), to the end of the wire coming out of the plug it will tell you if that is the problem.

[Big Secz 26]

Ok....I hope this helps. I took both '70 and '71 wiring diagrams and color coded them real quick to show where each circuit goes.

 

You will have to save them to your computer and blow them up. If you can't read them send me a PM your email and I will send you much larger version. I had to reduce the size to meet the file requirements of the forum.

['70MACH1 10]

:yes:Been too busy to get to it today, but I have the rest of the week to work on it. I like the colored coded diagram much better to read than the one I have, an old Chilton's. Thanks.. I'll get it.