Ignition Switch Bites the Dust

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sdpatt

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Here's another one of those stories where you wonder how long a part can last before it finally gives up and quits. As my 5 year old daughter and I pulled up to Pep Boys on a trip to check out their battery chargers (mostly for the boat battery), I was unable to turn the key far enough to stop the engine. Something was hanging up in the steering column. After wiggling and twisting the key a bit the engine turned off, but another twist of the key found it unable to start. Uh oh.

I called my wife and had her bring a few selected tools to remove the steering column shrouds and to give Pamela a ride home. I could always push start the car if necessary, but I was parked in front of a car parts store so I would have been a little embarassed to have to resort to that and would probably need to return for the parts anyway. Even before the calvary arrived, I used a long shafted vent thermometer to remove the ignition lock cylinder. I had installed that Ford part only a year ago and it already seemed loose.

Now on my own, I bought a Borg-Warner ignition lock cylinder replacement at Pep Boys and found that the car would start, but it required that I turn the ignition key to a certain point near full lock - just enough, but not too far. The ignition switch had apparently failed and was preventing smooth motion of the slide switch inside and only making a small piece of conductor availble to make the starter circuit. I reinstalled the Ford lock cylinder and was once again unable to engage the starter. The lock cylinder was loose enough not to manipluate the switch far enough to engage. I re-entered the store and purchased a Borg-Warner ignition switch and headed home to install the new switch. For a little over $30 in parts, the SHO should be back in business.

Upon disassembly of the old switch under the steering column, I found that the original had overheated and melted on two sets of spade terminals. So to answer the question about how long the ignition switch might last, about 15.5 years. The original ignition lock cylinder laster about 14 and the Ford replacement about 1(!) year. I cleaned up what I could on the female portion of the connector and installed the new switch.

A test start found the combination of the new lock cylinder and switch to function "as good as new." I am once again thankful that Ford designed the SHO to be a rather simple machine to troubleshoot and repair and even more thankful that God provided me the abilities to take care of it.

Back on the road again....

P1010098(640x480).JPG
 
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mrecoolgar

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I hate when that happens.
But sounds like a quick and knowledgeable fix.

I remember wanting to leave after refueling only to find no power at all.
There was a storm approaching and all windows and moon roof were open.
It got towed away in time and found to be a main fuseable link.
How it happened thou I still don't know.
 

jelloslug

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On my '90 I had to completely replace the connector and the switch. The plug had melted so far that it actually had charred and crumbled apart when I tried to remove it from the switch.

Melted20plug
 
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sdpatt

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It looks like it was the same termnials that overheated on both of our switches. I have been wanting to look at the schematic to see what circuits got so hot.
 

masho95

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sdpatt said:
It looks like it was the same termnials that overheated on both of our switches. I have been wanting to look at the schematic to see what circuits got so hot.

It looks like it's pins: B2, A2, B4

Still looking through my books to find out what they go to.

Edit: I keep looking through my books but for some reason can't find what the pin outs go to.... errg
 
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jelloslug

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sdpatt said:
It looks like it was the same termnials that overheated on both of our switches. I have been wanting to look at the schematic to see what circuits got so hot.


Yes they are the same terminals. Almost all Fords of this vintage have problems with the ignition switches; there was even a big recall in the early to mid '90s to replace them on most models because of fire hazards. The larger pin on the right in your pic controls the starter solenoid. The 2 in the middle feed fuses 5 and 9. Fuse 5 is a 15 amp fuse that runs most of the electronic systems in the cabin and fuse 9 is a 30 amp fuse that is for the blower motor.


masho95, the pin out is located in the section for troubleshooting the ignition switch, multifunction switch, and tranny selector switch.
 
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zacritz929

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how do you remove the top part of the steering column cover? my turn signals arent working and i want to check out the MFS but i dont see how the top plastic piece comes off.
 

cub1947

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Would really appreciate some assistance, have not been able to locate a wiring diagram, and my plug fell into so many pieces that I can only place about 4 wires in the new plug with certainty. My '90 was down for several months until i found where to get a new connector, and now due to a water disaster at the house, my manuals are AWOL. Thank you in advance for any help.
 

auto.guru

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i had my key get busted off in my ignition cyl. it was about 1 hours worth of work feeding a broken key into the cylinder to turn it foreward, to remove it.
 

SHOtimer

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Would really appreciate some assistance, have not been able to locate a wiring diagram, and my plug fell into so many pieces that I can only place about 4 wires in the new plug with certainty. My '90 was down for several months until i found where to get a new connector, and now due to a water disaster at the house, my manuals are AWOL. Thank you in advance for any help.

You'd be best to start a new thread.

Doug
 

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