MarineEngine.com - Your online store for all types of marine engines and boat parts.
PHONE ORDERS
Monday - Friday
9:00 AM - 5:00 PM EST
Click for TOLL-FREE Number
Online Checkout
Special $9.95 Flat Rate Shipping
(800) 209-9624 | Home | Contact | Shipping | Returns | Cart View your shopping cart.
Part Number Search
Shop by engine/drive part number.
Original & matching parts for sale.
Manuals & Accessories
Shop by description, item number
or manufacturer's model number.
Boat Repair Forum Boat Repair Forum   Boat Video Gallery Video Gallery
   
Click for Crusader parts and manuals!
Results 1 to 17 of 17
  1. #1
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default How do I eliminate the oil pressure shut off switch? 1993 454

    I have 1993 twin 454 xl crusaders and when coming in from off shore yesterday the low oil alarm went off and shut down port motor. Oil level was fine with no indication of leaks. Motor would crank but no fire was coming out of the coil. This was a shut down in the middle of a storm and I want to remove this option and rely on buzzers and a gage so this wont happen again. I have a brass tee coming out of block with a canister style sending unit with one wire on one end and smaller sending unit with one wire coming out of the other end of the tee. In your opinion, want can I do to fix this problem. Thanks.

  2. #2
    Join Date
    Jul 2010
    Location
    Canada
    Posts
    630

    Default Re: How do I eliminate the oil pressure shut off switch?

    If you have an electric fuel pump then it's not a "problem" as you stated. It's actually a safety feature that is required to be there so that when the engine shuts down for some reason, fuel supply is stopped to prevent a possible explosive situation. I don't recommend changing this setup but it does help to know what to do with it if the fault is in fact a bad switch while out at sea.

  3. #3
    Join Date
    Jun 2010
    Location
    Ocean City NJ
    Posts
    55

    Default Re: How do I eliminate the oil pressure shut off switch?

    the larger oil canister sender is for gauge, the smaller is for alarm http://www.marinepartssource.com/cru...454xlikp25.asp

    try removing the wire from the small sender, it should still start, the sender may be grounding the coil or an ignition circuit when low pressure is detected. you might have a relay in the circuit that controls that circuit so a cold start can occur. I would be curious on the low pressure, might just be a bad sender if the gauge still read ok

  4. #4
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch?

    Thanks, I am heading to the boat and I am going to clean all of my grounds, install a new sending unit and try the alarm wire. I will log on this evening at let you know what happens.

  5. #5
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    5,534

    Default Re: How do I eliminate the oil pressure shut off switch?

    I'd suspect the oil pressure switch is fine. The buzzer went off due to lack of oil pressure from the engine stopping (from lack of spark).

    I'd look for no reference signal from the distributor; if absent, I'd start with the pickup coil inside the distributor.

  6. #6
    Join Date
    Nov 2002
    Location
    Mullica Hill, New Jersey, United States
    Posts
    1,810

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    You do not have an oil pressure shut off switch. The oil pressure alarm sender does not turn off the fuel pump or the ignition system. That engine has a separate oil pressure switch on the left side of the block near the front which prevents the fuel pump from running until pressure is present. Changing the alarm sender will not change anything. I agree with Mark, it sounds to me like you have other issues.
    Last edited by linesix; 12-20-2010 at 05:15 PM.

  7. #7
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    Just came back and found out several things. First removed alarm wire and then sending unit wire and still no fire. Found that when turning motor with switch, pos side of coil is hot, but no spark is coming out of coil wire. Thought that coil was bad, replace w/ new coil but with the same out come, no fire coming out of coil. Can this be grounded out threw some other safety device? I will go back tomorrow and track wires to see if there is another pressure near the front of the motor and check back in. Thanks for your help

  8. #8
    Join Date
    Nov 2002
    Location
    Mullica Hill, New Jersey, United States
    Posts
    1,810

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    THERE ARE NO SAFETY SWITCHES THAT INTERRUPT THE IGNITION SYSTEM, DON'T WASTE YOUR TIME LOOKING FOR ONE. You have an ignition issue.

  9. #9
    Join Date
    Jun 2006
    Location
    Westford, MA, US
    Posts
    28

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    [THERE ARE NO SAFETY SWITCHES THAT INTERRUPT THE IGNITION SYSTEM, DON'T WASTE YOUR TIME LOOKING FOR ONE. You have an ignition issue.]

    Not sure I agree with that statement. Both my present 454s and my prior 460s have/had low oil pressure shut down switches. No alarms. When I lost the oil in one engine (hole in pan), it shut down. Would crank, but not start, due to low or actually, no oil pressure. When installed 454s, included switches but experienced long cranking periods until oil pressure built up. Installed continuous duty solenoids (normally closed) in line with the switches. Solved the starting problem. Wire runs to coil and grounds coil when pressure drops. Switch is teed with oil pressure sending unit.
    If it doesn't interrupt the ignition circuit, what does it do?

    East Coast may have both an alarm and a low pressure shut down-separate sending units.

    Gene

  10. #10
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    OK, so should I start by tracking the alarm and sending unit wires to see if the is some sort of shut down switch (toward left front of motor)? Also, I have four wires coming off of my coil. + & - go to the dist.(mallory prestolite w/ new cap & rotor), and the other + & - goes into a large group of wires in a cover. Should i track these wires and see if the have a cause behind the fire out of the coil? Or , are those wires just coming from the ignition? I just don't get how there is fire into the coil, but no fire coming out of the coil wire. Unless it's grounded out or shut down somehow. Tell me what you think.

  11. #11
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    I forgot to add this, after puting the alarm & sending unit wires back on, I cranked the motor. While cranking, I did build up oil pressure, approx. 25 lbs. Another q, if I do have an auto shut down, or something that grounds out the coil, how do i reset it?

  12. #12
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    5,534

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    The setup comogene describes is a modification from the factory configuration.

    As far as troubleshooting the ignition system, it would be best to figure out if you have a mallory or a prestolite (there isn't a "mallory prestolite") and figure out if it is the older point type or the newer 'breakerless' style.

    Generically, you need to have B+ to the positive post on the coil, from the ignition switch, and the negative post gets grounded, either thru the points or the breakerless unit. You may have a ballast resistor that has burnt out. A bad tachometer is another possibility (usually connects to the negative post on the coil-grey wire); you can just leave it disconnected. If the distributor has points, check their contacts to make sure they aren't burnt and check the gap, too.

    Another valuable tool to have is the factory manual. Andrew, our web site host, offers these and can be reached via the 800 # at the top of the page.

  13. #13
    Join Date
    Jun 2010
    Location
    Ocean City NJ
    Posts
    55

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    Is this a carb or throttle body engine, also is your coil round or square, 93 454xl shows delco distributer and is electronic. Did I miss some where you have an older model?

  14. #14
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    Just got back from the boat and discovered a "oil pressure switch(fuel pump) #98220 that is located on the left side of the motor just in under the alternator. It has two purple wires and one yellow/red wire which plugs into a harness that runs from the sending unit and alarm along the block and into this switch that screws into to block. Now that I know that I have a shut down switch, my question is still. how do I by-pass this to keep the enigine from going into shut down mode. I would prefer to rely upon a buzzer and light system.

  15. #15
    Join Date
    Dec 2010
    Location
    Sebastian, Fl
    Posts
    12

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    It is a 1993 454 XL. It has rochester quadjet carbs. The tap on the dist. says prestolite and when I ordered nes dist. caps they were mallory. The coil is round and like a ford coil and with two post and holr for the coil wire.

  16. #16
    Join Date
    May 2010
    Location
    DC Burbs/Maryland Eastern Shore
    Posts
    790

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    I don't know whether you're in the charter business, but I would tend to think that if anything bad happens and your insurer finds out you bypassed the engine safety shutdown.....just sayin.
    Practicing the ancient art of ren-ching

  17. #17
    Join Date
    Nov 2002
    Location
    Mullica Hill, New Jersey, United States
    Posts
    1,810

    Default Re: How do I eliminate the oil pressure shut off switch? 1993 454

    Quote Originally Posted by East Coast Charters View Post
    Just got back from the boat and discovered a "oil pressure switch(fuel pump) #98220 that is located on the left side of the motor just in under the alternator. It has two purple wires and one yellow/red wire which plugs into a harness that runs from the sending unit and alarm along the block and into this switch that screws into to block. Now that I know that I have a shut down switch, my question is still. how do I by-pass this to keep the enigine from going into shut down mode. I would prefer to rely upon a buzzer and light system.
    That is an amazing discovery. That it the switch I described in the prior post. This is the last time I will repeat this: It does not interrupt the ignition, only the fuel pump. Here is the diagram. You have a 3 wire sender but the system is the same. Also, it does not run to the other senders, it only runs by them en route to the main engine harness. As a Crusader dealer I am not taking the liability of explaining to you how to bypass a safety system that will allow your electric pump to run constantly, any time the ignition switch is on. If you want to do that, you're on your own.

    Click image for larger version. 

Name:	Classic Wiring.jpg 
Views:	429 
Size:	37.2 KB 
ID:	1497

Similar Threads

  1. 4.3 Safety shut off Switch and Oil Pressure
    By reeter in forum Mercruiser Sterndrive Forum
    Replies: 2
    Last Post: 06-20-2010, 10:13 PM
  2. Replies: 16
    Last Post: 07-27-2009, 08:18 AM
  3. How to shut off 1990 30hp Evinrude without the lanyard kill switch
    By rick_roth in forum Johnson Evinrude Outboard Archive
    Replies: 1
    Last Post: 03-17-2007, 05:25 PM
  4. Ignition Switch wonbt shut down motor
    By reidster in forum Mercury Mariner Outboard Archive
    Replies: 4
    Last Post: 03-14-2007, 07:35 PM
  5. Mercury 1993 25 hp switch box
    By alsoares in forum Mercury Mariner Outboard Archive
    Replies: 1
    Last Post: 01-16-2007, 10:52 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •