No power to the port engine ignition switch

Discussion in 'Electrical Stuff' started by hafnutz67, Aug 1, 2019.

  1. hafnutz67

    hafnutz67 Member

    70
    Jan 30, 2017
    Plano, IL
    1998 270 Sundancer
    Twin 4.3, Alpha One
    In need of a little help here. We have a 98 270 Sundancer wide body with twin 4.3’s. I haven’t started the engines in about 6 weeks. No issues at that time.
    Since then I replaced the dash panels and VHF radio. I decided to start the motors tonight just to make sure there weren’t any issues before the weekend (I do this every time before a boating weekend). I started the starboard engine first and let it warm up. When I went to start the port engine, nothing. I checked all 3 batteries and they are all charged. I pulled the panel with the ignition switches to see if the switch is bad. There’s no power going to the switch so I checked the breaker and no power to it either. I traced the wire back to the plug and there’s no power at that pin either.
    Looking for ideas or suggestions as to what it could be or what to check next.
    Thanks in advance for any help you can give.
     
  2. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass, cape coral fl
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Battery power goes from the 90 amp fuse on the starter to the 50amp breaker (red). Leaves the breaker as (r/p).

    So if you have no power to the 50 amp breaker you probably blew the 90 amp fuse.
     
  3. Mike sandor

    Mike sandor Active Member

    163
    Jul 28, 2017
    Eau Claire, Wisconsin
    2007 320 Sundancer
    Twin 496. Bravo 3
    2018 3500 Chevy, Loadmaster trailer
    Raymarine Axiom, Quantum 2
    496 Mercruiser/Bravo III drives
    What Scoflaw said....... I had a similar problem, the fuse on the starter was fine, the 50 breaker would reset but not pass power. No 12 volts to the motor. Replaced breaker, all is right in the world!
     
  4. hafnutz67

    hafnutz67 Member

    70
    Jan 30, 2017
    Plano, IL
    1998 270 Sundancer
    Twin 4.3, Alpha One
    Ok, I checked and I have power to the 90A fuse on the starter and power to the 59A breaker on the engine. I also have power on both sides of the 90 A fuse on the starter.
    I decided to try connecting the positive feed that goes to the SB ignition to the port ignition as it had power. I then turned the port ignition switch to run (not start) just to see if the alarm would sound and the gauges would turn on (to see if it was an issue with the port ignition positive wire). Unfortunately nothing happened and now there is no power at the SB ignition positive feed.
    Every other positive feed at the ignition panel still has power (horn, blowers, etc.)
     
  5. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass, cape coral fl
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    The red/purple is the 12v feed to the ignition, and there should be a fuse in that line. So if you have 12v leaving the 50 amp breaker test it along the way to see where you are losing it
     
  6. Mike sandor

    Mike sandor Active Member

    163
    Jul 28, 2017
    Eau Claire, Wisconsin
    2007 320 Sundancer
    Twin 496. Bravo 3
    2018 3500 Chevy, Loadmaster trailer
    Raymarine Axiom, Quantum 2
    496 Mercruiser/Bravo III drives
    8A90586D-B650-41D4-8AB8-70D8EEFFA127.jpeg I had this fuse blown. Located on the top of the engine
     
  7. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass, cape coral fl
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    His weather pack will look different than yours, located in about the same area. Those 3 fuses are for fuel and ignition and will have nothing to do with his "no crank" power to the ignition switch.
     
  8. Phasma

    Phasma Phasma2128 GOLD Sponsor

    604
    Sep 17, 2016
    West Michigan
    2003 360 Sundancer
    Mercruiser 8.1s Horizon
    This maybe a little basic.....no insult intended. Are your shifters in neutral?
     
  9. scoflaw

    scoflaw Well-Known Member

    Aug 10, 2011
    cape cod mass, cape coral fl
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    That will stop the " crank" but he has no power at the ign.switch on the red/purple wire. The voltage transfer begins there.
     
  10. hafnutz67

    hafnutz67 Member

    70
    Jan 30, 2017
    Plano, IL
    1998 270 Sundancer
    Twin 4.3, Alpha One
    Thanks for the replies. It really helps.
    scoflaw is correct, the issue wouldn't be at the neutral safety switch as that feed is after the ignition switch.
    Looking at the schematics, it doesn't appear to be any in-line fuses. If so, they are not spelled out on the schematics.
    I will check all of the fuse tails as at the engines as Phasma suggested just to make sure.
    Following the positive feed from the battery all the way to the port ignition switch (highlighted orange on the attached schematics), I am now leaning towards it being an issue at the Plug/Cap #1 behind the helm. It is very possible that this plug worked partially loose when I was replacing the dash panels, especially when I was removing zip ties and pulling on wires to get enough slack in the depth gauge wire to relocate it to the port side of the dash. The fact that I had unplugged and plugged that one back in the other night when I was trying to find the issue at the port switch could explain the fact that I now don't have power at the SB switch either. That was a PITA to get at with both hands I pushed it back together with one hand as it was getting dark and I had to get the boat covered back up.
    That would be the only plug that would explain both of the switches not getting power as after that plug they split up into two different circuits (Plugs/Caps #36 & #37). Also, everything else at the ignition panel (horn, blowers, trim tabs, etc. still have power.
    I'll check that after work and hopefully that is the issue. Otherwise I think I'll have to trace both circuits all the way from start to finish and check both wires for power at every plug.
     

    Attached Files:

  11. hafnutz67

    hafnutz67 Member

    70
    Jan 30, 2017
    Plano, IL
    1998 270 Sundancer
    Twin 4.3, Alpha One
    Well it’s not plug 1, 36 or 37.
    Still chasing gremlins
     
  12. hafnutz67

    hafnutz67 Member

    70
    Jan 30, 2017
    Plano, IL
    1998 270 Sundancer
    Twin 4.3, Alpha One
    Just to update. I did get everything figured out Saturday.
    There are 15A fuses behind the carbs just past where the big black ignition wires plugs are.
    The port fuse was blowing due to a ground wire mounted at the wrong post on the back of the sync gauge.
     

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