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1971 Clark C500-45 Forklift will not start

inspectweld ยท 2019-02-17 14:11

I have tested for spark on my plugs and I have no spark. Tried cleaning and then replacing the points and condenser and replacing the coil. Still no fire on the plugs. Any help- would be appreciated. On the plus side of coil with key on I get 30 volts and while cranking I get a draw down to 25 volts and it holds steady at that voltage. Neg. side of coil with key on I get 1 volt and while cranking I get a pulse from 1 to 2 volts. Just out of curiosity I disconnected the neg coil wire from the connection to the condenser wire on the points and I now get 30 volts on that connection and at the neg. terminal of the coil. With that wire still disconnected when I crank the motor it draws down to 25 volts and holds steady. On the positive side of the coil with the key on it does the same thing, I get 30 volts and it draws down to 25 volts and holds steady

Replies24
  1. #1BillG2019-02-17 16:33

    Well first off this is only a 12 volt system. What are you using for a voltmeter analog (needle) or digital (numbers)? Do you have a battery charger connected to it and if so what voltage setting. These are a standard ignition system, nothing special. Ignition switch to + side of coil and - to the distributor. Some have a resistor for running and a bypass for starting on the starter solenoid but that's it.

  2. #2inspectweld2019-02-17 17:01

    Its a multimeter needle type and I have it set on DCV in either the 0-10 or 0-50 range. No battery charger just a fresh charged 12 volt battery.

  3. #3BillG2019-02-17 17:08

    In the 0-50 range you should be reading approx. 12 volts. I don't know where you are getting the high readings. Go directly to the battery and you should read about 12.6 volts on a good battery.

  4. #4inspectweld2019-02-17 17:12

    I was about to add that I already did that and its 30 volts at the battery. I was thinking the same as you, that it should be about 12. There must be something wrong with the meter. But regardless it seems the voltage drops when the neg. from the coil is attached to the condenser and points. Should the voltage drop when connected to the condenser and points?

  5. #5BillG2019-02-17 17:20

    Do you have an ohmeter scale or a test light?

  6. #6inspectweld2019-02-17 17:23

    No light but the meter has an ohm setting, Im not at my shop now to check anything else now.

  7. #7BillG2019-02-17 17:29

    Disconnect the - wire that goes from the coil to the distributor. Zero your ohmeter and turn the engine over until the points open. Place one probe of your tester on the distributor frame and the other probe on the wire that you removed that goes to the distributor. And see what the resistance is, it should be infinity(looks like a figure 8 laying on its side) or no continuity. All this does is check for any shorts in the ignition points and condenser.

  8. #8inspectweld2019-02-17 17:36

    This is the same type meter I have. Do you want the wire tested while it is connected to the condenser or while it is disconnected?

  9. #9BillG2019-02-17 17:42

    What distributor do you have Delco or Prestolite? Either way you need to connect one lead of your meter to the lead going between the distributor and coil and the other lead of your meter to the frame of the distributor. You don't disconnect from the condenser because this would eliminate it from the circuit.

  10. #10BillG2019-02-17 17:46

    I just noticed you don't have an ohmeter, it's only volts and ma.

  11. #11BillG2019-02-17 17:47

    Or maybe I just need better glasses.

  12. #12inspectweld2019-02-17 17:47

    I read what you wrote again and I think I see what you want. Disconnect the neg. coil wire that goes to the points and put my positive lead on on end that I disconnected and the neg. lead on the dist. body while on ohms position on the meter, correct?

  13. #13inspectweld2019-02-17 17:49

    Its hard to see but ingraved in green between OFF and 0.5

  14. #14BillG2019-02-17 17:49

    Correct, just make sure your batteries are good, touch your leads together and see if the needle swings to zero.

  15. #15inspectweld2019-02-17 17:54

    So what does the needle do if I have a short? What does it do if I dont have a short?

  16. #16BillG2019-02-17 18:00

    If you have a short or minimal resistance it will swing toward zero. This will indicate a shorted wire, condenser or points insulator. Just make sure the points are open.

  17. #17inspectweld2019-02-17 18:04

    If I have a short what should I do next to repair or troubleshoot? If I do not have a short what should I do next to troubleshoot?

  18. #18BillG2019-02-17 18:08

    If you have a short you will have to determine it by disconnecting things until the short goes away, points, condenser and maybe the wire itself where it goes into the dist. If you don't show a short, roll the engine over until the points close and see if you have continuity (short) then.which you should have.

  19. #19inspectweld2019-02-17 18:12

    Ok I will try that tomorrow morning. You mentioned a points insulator, exactly what is that?

  20. #20BillG2019-02-17 18:15

    That's at the pivot point of the contact arm, it should be insulated from the support by a narrow insulator, it's part of the point set when you buy them. Again without knowing which distributor you have I can't be more specific.

  21. #21inspectweld2019-02-17 18:19

    It should be Delco, I know the starter relay has a Delco stamp on it

  22. #22BillG2019-02-17 18:23

    There were many different types of Delco distributors used, take a picture and post it.

  23. #23inspectweld2019-02-17 18:27

    OK thanks so much for your time, I will do that in the morning, I have lifts to make with that forklift

  24. #24inspectweld2019-02-27 21:42

    Just thought I would check back in and thank for the help again and let yall know what the problems turned out to be. The wires of the condenser and coil wire were shorted out. After I got fire back to the plugs it still would not start. I sprayed some carb. cleaner in the air intake and got it to start and run shortly but it would not stay running but a second or two. Luck have it, one of my customers ace mechanics came to pick up a welding job I finished for them and he took a peek at it. He determined that initially I had a bad coil and I fixed that problem when I replaced the coil but when I changed the points the wire connectors were connected on the wrong side of the insulator. The reason it did not want to start was because it was kind of cold that morning. He said the rubber diaphragm in the carburetor is very old and is getting hard and loosing its flex especially in colder weather and its getting worse as time goes by. He said until I replace the diaphragm I can use a light bulb or electric heater to warm up the carburetor diaphragm and it should crank right up. So far he is correct