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Dino Saga 050911 _ Ignition switch, alternator, regulator, starter, flasher

Discussion in 'Corbani's Corner' started by John Corbani, Sep 11, 2005.

  1. John Corbani

    John Corbani Formula 3
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    May 5, 2005
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    John Corbani
    #1 John Corbani, Sep 11, 2005
    Last edited by a moderator: Sep 7, 2017
    Dino Saga 050911 _ Ignition switch, alternator, regulator, starter, flasher

    Electrical problems have been few but some have been persistent. Ignition Switch, Alternator, Voltage Regulator, Flasher, Light Grounds, and Starter in order of occurrence. Let’s take them one at a time.

    I bought the car at 51,000 miles and after another 5,000 the ignition switch would not make reliable contact with the starter contact. Might take two or three tries before the starter would kick. OK, after 14 years maybe it’s time to change. 50 bucks later FAF had me a replacement and I was back in business. Just for the fun of it, I took the switch apart and found the starter contact almost completely burned away. Plastic was fine, brass was gone. Curious.

    Drove the car for another 25,000 miles and the problem came back. I pulled the switch, carefully unriveted it and found the brass starter contact badly eroded. Pulled contact, brazed some rod on contact, filed to original shape and put back together. The hollow rivets can stand 2-3 re-workings. Took that many tries to get contacts and 1-time lockout just right. Time to run an experiment. I touched the starter wire to the battery wire and admired the beautiful arc when I broke the contact. That was where the brass was going. A Flyback diode was needed. I put a silicon diode from the starter wire to ground, cathode to starter wire, and no more arc. When you break the current going to a starter solenoid, there is a huge negative spike and the energy in that spike was killing the switch. The diode catches the spike so no voltage, no arc. Just make sure the polarity is right and the diode is rated for 3 amps or more. Radio Shack is fine. I put everything back together and have run 100, 000 miles without a miss.

    The alternator needs the brushes changed every 20,000 miles. Oil gets in there no matter what you do. Air pump clutch was gone so alternator should come right out, right?. First time I pulled the right gas tank. Makes it easy but no fun getting tank in and out. Noticed that there was a relief in tank wall. By George, take out the water line from the oil cooler and the alternator can be worked out and back in. Go slow. Local shop charges $65 and takes a day to clean things up, put in brushes and get it back. 30 min. out and 45 min. in including putting coolant back. Put wires on alternator BEFORE putting it back in!

    Original voltage regulator was electromechanical and it eventually gave up. Pep Boys had a 3 terminal Chrysler regulator. Works fine. Only one screw mounting but it hasn’t gone anywhere in 10 years.

    Flashers die. Common thermal flashers sometimes do not work when new. Don’t agonize, buy a couple and use the ones that work. Pep Boys again.

    The car has been bent many times. Never at speed so damage has been superficial. Left front has had a real hard life. After every repair or re-paint, the lights don’t work. Weird things happen when light grounds are missing. Clean the metal under the lug, use gell or grease, all will be well.

    The starter finally went through its brushes at about 150,000 miles. Son of a gun to get out the first time. Pull the rear exhaust header clean out before you even touch the starter bolts and it is a snap. I spent half a day trying to wiggle it out with header in place. Alternator shop got it back to me in a day. No problem getting it back in.

    First picture shows back of ignition switch and regulator mounting. Diode goes from white starter wire to ground. Shrink tubing protects diode. Brown flexible wires carry current. Camera was against the accelerator pedal.

    Second picture shows label on bottom of radio. Got tired of figuring which wire goes where on the ignition switch and put the info where it would do the most good.

    John
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  3. Kram

    Kram Formula Junior

    Jul 3, 2004
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    Mark
    John, a great post. I really like the inclusion of a diode in the circuit, very nice. If only Pep Boys knew they were building a Ferrari out of their Chrysler parts catalogue!
     
  4. synchro

    synchro F1 Veteran

    Feb 14, 2005
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    In the first photo above the words "IGNITION SWITCH" there is a red wire with a mini switch on it - what does that do?
    THX
     
  5. John Corbani

    John Corbani Formula 3
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    Goes to radio. Radio has two hot wires. One keeps memory and clock alive. Other activates time display, lights and sound. I used to leave time display on all the time but found that it ran battery down in about a week. I used to slde switch to off when I went out of town. Forgot it too often and moved that red wire to ignition on. Slide switch is always on now. Battery will keep charge for months. Was too smart by half.

    John
     
  6. DinoDriver

    DinoDriver Formula Junior

    Mar 14, 2005
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    Bill Ebert
    John, your posts always amaze me! You are a freakin' genius! I and several pretty smart carguys have been trying to figure out the "starter won't engage problem" for years. Your analysis and "cure" was very perceptive, logical and clever. I'll probably take my used ignition switch apart this weekend. Need more details on that diode . . . what do I ask for at Radio Shack?

    Now tell me why the engine ocassionally continues running for 10 seconds to a minute AFTER the key has been turned to the Off position. Bad (worn) key cylinder, therefore not fully turning the switch to the OFF position? 64,000 mile Dino.

    Bill
     
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  8. John Corbani

    John Corbani Formula 3
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    No idea of why engine should run on after swich off. Might be a funny switch or lock. Put a voltmeter on hot wire coming out of switch. If voltage stays up after switching off you have the answer. If not, you have to see if voltage is on coil. Go from there.

    Diode across starter solenoid is a silicon diode rated at 3 or more amps and 50 or more volts. Make sure of polarity or there will be a very quick explosion as the diode dies. White band goes to switch, other end goes to a good frame ground. Leads should be no more than a couple of inches long. #20 wire is big enough.

    Good luck,

    John
     
  9. DinoDriver

    DinoDriver Formula Junior

    Mar 14, 2005
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    Bill Ebert
    John, thanks for the ideas. I'll give them a try once I get everything back together - - obviously not this weekend!

    Bill
     
  10. synchro

    synchro F1 Veteran

    Feb 14, 2005
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    It looks like the diode is connected from ground to a red wire that goes to the radio microswitch. Am I seeing this incorrectly or is the red wire connected to the white, starter wire?
    Thank you
     
  11. John Corbani

    John Corbani Formula 3
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    Scott,

    You are seeing incorectly. Top end of diode in picture goes to a wire nut combining all grounds. Bottom end of diode is soldered to a medium brown wire that is crimped to the large white wire that goes to starter solenoid. I just cut insulation away on brown wire and soldered small brown wire from diode to it. Left it uninsulated since nothing could touch. Tens of thousands of starts later all is OK. Red wire is behind brown wire and is only for radio as is little slide switch.

    John
     
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  13. 4redno

    4redno Formula 3
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    Mar 21, 2006
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    Keith Mitchell Wintraub
    John:

    I had my starter solenoid repaired and while it works much better, there are still times when I turn the key and the starter motor doesn't engage. It could be my ignition switch as noted in your thread.

    My questions:

    1) What happens inside the starter switch that would cause it to fail?
    2) What does the diode do? What does the cathode do? Clearly, I missed that lesson in school!
    3) Where are the hollow rivets you mentioned - in the ignition switch or the starter solenoid? I thought the replacement switch could be remove with two screws!
    4) Can you recommend part number for the diode and cathode and other specifications which ensure that I get the right kinds?
    5) I see that you put a silicon diode from the starter wire to ground. I know the cathode goes to the starter wire but where does it come from?
    6) Do the diode and cathode attach to one another?

    Your assistance is greatly appreciated. While I can take stuff apart on my Dino and put it back together without screwing up too badly, having the expertise to source problems and find a cure is something that I leave to experts like you!

    Thanks...Keith
     
  14. John Corbani

    John Corbani Formula 3
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    Lots of questions over the months since I posted this. I will try again with better pics this Sunday (11/4/07) but as a quick answer to some questions, here goes.
    Switch is a Bosch part that was/is used on many cars. The switch is held to the lock mechanism by two screws (straight slot). The switch contacts that go to the starter solenoid will self destruct over time. I use the car as a daily driver and probably have more starts than most. Today I went looking for a Timex watch and stopped and started 21 times. It adds up. And I didn't find the watch.

    After buying the first replacement I opened up the dead one and found what happened. The Brass/Bronze contacts were badly eroded. Maybe by the spark generated by the solenoid? New switch died after 20,000 miles. Opened that one and same problem. This is a common problem in industrial control relays. My busines for 19 years. Simple cure: add a diode across the coil causing the spark. Ancient technology. Figured I could repair the switch, add a diode and be back running in hours. I was right.

    The diode I used was a 1N4004 bought from Radio Shack. Any Silicon diode rated for more than 3 amps surge and 100 volts is fine. The diode is a small cylindrical plastic package with two leads coming out of it's ends. One of the ends has a band on the body. This is the Cathode end of the diode. The other end is called the Anode. Connect the cathode of the diode to the wire going to the solenoid. Connect the anode to ground. Erosion problem solved forever.

    I opened the switch body by carefully unrolling the hollow rivets holding everything together. Be carefull opening things because there are springs in there and the "one time" mechanism has both springs and ball bearings. I unbent swages on contacts, removed them, and brazed new material on burned contacts. Getting everything back to original shape and getting it all back together required a lot of patience and technique. Not a job for those who have never done similar things before. Better to just spend the $50-$100 to get a new one.

    Once done, life has been good. 100,000 miles and maybe 30,000 starts. Fix worked. Folks who do 1,000 miles a year don't have these problems until the car is 30 years old. Most everybody is there or getting close. Hope this helps.

    John
     
  15. synchro

    synchro F1 Veteran

    Feb 14, 2005
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