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9/02/2017 12:30 PM  #1


Defective ignition switch?

I have a problem with my 1964 Falcon. It is equipped with a rebuilt 1965 289 (from a donor Mustang) and a top loader. Mustang Steve's clutch cable and pedal kits have been installed. I started it for the first time three weeks ago, but have been too busy to work on it since. It sounds very strong. I have installed a one wire alternator and done the rewiring with a M.A.D. Electric wiring kit.The GEN light actually goes out when the engine runs!

The problem: The original ignition switch fell apart three weeks ago, so I replaced it with a Standard brand switch today. The switch went in with little problem. This morning I started the engine with the new ignition switch. I had inadvertently reversed the 'I' and 'S'  starter solenoid terminal wires. After straightening this situation out, the switch operated flawlessly. However, when I turned off the ignition and removed the key, the engine continued to run. I had to disconnect the coil-to-distributor wire to shut it down.Could I have damaged the switch?
Can the switch be defective? What other conditions could cause this to happen?
 

 

9/02/2017 4:03 PM  #2


Re: Defective ignition switch?

Sounds like the switch.  Its possible you damaged it by hooking it up wrong, but it really doesn't matter.  Electrical parts are non returnable once they've been installed. 

I'm trying to think of a scenario where the switch isn't at fault, but I really can't. 

 

9/02/2017 5:06 PM  #3


Re: Defective ignition switch?

I never heard of it happening but I suppose the "I" contact in the solenoid could be stuck.  That would hold 12V to the coil at all times.  You can test by disconnecting the wire to the "I" lug on the solenoid and then re-attach the coil wire and fire it up normally.  You don't actually need the "I" terminal power most of the time for starting...it is there to provide full 12v for cold starts where the batt voltage might be pulled abnormally low.

Wondering...is that replacement switch a OEM type or just a keyed OFF-ON-START switch?

BB


"you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
 

9/02/2017 5:24 PM  #4


Re: Defective ignition switch?

I'm with Bullet Bob. If the solenoid sticks it can cause the current to backfeed and keep the engine running after the key is turned off. If it happens again, the official treatment is to first whack the top of the starter solenoid (on inner fender near battery) to see if you can dislodge a stuck relay. If that doesn't work to make the engine die, pull the small wire (bown one, I think) off the solenoid that goes to the coil. If that kills it, then the cause is stuck starter solenoid. If it continues to run, then suspect the key switch.

I have seen starter solenoids cause this problem, but a bad ignition switch in my experience results in a no-run condition. Anything is possible, though.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

9/02/2017 6:28 PM  #5


Re: Defective ignition switch?

Thanks for the input, gentlemen. I will be home again in two weeks and will tell you what I find. The ignition switch is the Standard Brand. It is the ACC-OFF-ON-START configuration.It worked as designed until...you know. The solenoid is new, also.
I've smacked solenoids before and will try that method and the others when I return.
Tommy2x4

     Thread Starter
 

9/05/2017 4:26 PM  #6


Re: Defective ignition switch?

The latest from Mark Hamilton at M.A.D. Electrical is that I may need to install the diode he provided in his wiring kit at terminal 1 of the alternator. I'll keep you posted in a few weeks.

     Thread Starter
 

11/17/2017 3:40 PM  #7


Re: Defective ignition switch?

Gentlemen,
I found that I had wired the battery directly to the positive post of the coil. Problem solved. Thanks for all the input. Tommy

     Thread Starter
 

Board footera


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