Join the C34 Association Today!
[C34 Home] [C34Tech Notes] [C34 Tech Wiki] [Join!]
Please login or register.
Advanced search  

News:

Pages: [1]   Go Down

Author Topic: Fuel Pump to Ignition Switch Wiring for M25XP  (Read 135 times)

0 Members and 1 Guest are viewing this topic.

Patches

  • Forum - Seaman Apprentice
  • *
  • Karma: 1
  • Posts: 9
    • View Profile
Fuel Pump to Ignition Switch Wiring for M25XP
« on: January 28, 2019, 10:28:50 PM »

My apologies in advance for the simplicity of this question, but I can't locate the answer from any wiring diagrams i've seen.

I have the M25xp engine, circa 1990, and am replacing the engine panel and wiring harness (both from CD).  I tossed the terminal strip and butt connected the harness to the new panel wires with marine heat shrink connectors.  I have suspended and secured the harness so that the weight of the harness is is supported--not by the butt connectors--but by securing the harness to the aft panel of the port lazarette.

My fuel pump is activated by a separate red wire which runs from the ignition switch on the panel.  I know because I removed it from the old panel.  And that's my problem because I don't remember which post I removed it from on the old ignition switch. Doh!

The switch on the new CD panel--like the old one-- has "on" and a "momentary" key positions, the latter which you hold to heat the glow plugs.  The "on" looks to be fed by the #10 "panel feed" wire off the solenoid "+".   The "momentary" looks to be fed by a white #10 which goes to the glow plugs.

Is the red wire to the fuel pump supposed to attach to the post on the ignition switch with the red wire (on), or the post with the white wire (momentary)?  My thought is to the same as the "red" (on) because that would mean it runs any time the panel is (1) "on" or (2) when engine is running.  If connected to the white (momentary) then the fuel pump would only pump if I was trying to preheat glow plugs.  But alas, my thoughts when it comes to things electrical are often "off."

Thanks in advance for your replies.

Patches   

 
Logged

scgunner

  • Forum - Petty Officer 2nd Class
  • ****
  • Karma: 0
  • Posts: 183
    • View Profile
Re: Fuel Pump to Ignition Switch Wiring for M25XP
« Reply #1 on: January 29, 2019, 08:12:15 AM »

     Patches,

        If I recall correctly the ignition switch is an automotive type, on and crank(momentary)which is not used because Catalina put a stand alone starter button on the panel. Where ever you connect the fuel pump wire it should be on and pumping when the ignition switch is turned to the on position.
Logged
Kevin Quistberg                                                 Top Gun 1987 Mk 1 Hull #273

KWKloeber

  • Forum - Master Chief Petty Officer of the Navy
  • ********
  • Karma: 30
  • Posts: 3088
  • "Positive Impact" 1984 C-30 #3573 trbsfk M-25
    • View Profile
Re: Fuel Pump to Ignition Switch Wiring for M25XP
« Reply #2 on: January 29, 2019, 08:40:30 AM »

P-

See wire #9 on the schematic on pg 30 of the XP Parts List manual, on the Wiki under "manuals"  **see note below
https://c34.org/wikiwp/

I don't like "loading up" the key switch, so I re-do a panel I put such things on anything that is made hot by the key -- hot side of gauges, hot side of a switch, etc.

The fuel pump wire is actually redundant -- both the alternator field excite (purple wire) and fuel pump feed are made hot by the key switch.  With new harnesses, I run one #14 wire and branch off in the engine compartment.  I have also fabbed a sort of dual terminal that plugs into the alt field excite male terminal and branches back to the fuel pump, but the fuel pump wire could be "hard tapped" as well.

[Edit - To prevent failure at panel terminals,] I create a harness bundle and zip-tie it to the back of the panel (typically to 2 gauge brackets and the tach) with zip ties. See Pic.

** As a new owner you need to know the dirty little secret about the engine vs. the boat.  The engine as purchased (and it's wiring) is just popped into the boat.  Manuals from Universal/Westerbeke are typically NOT personalized to Catalinas.  For instance panel schematics shown are typically for a Universal/Westerbeke panel, not a Seaward panel.  Note that the key/start/preheat wiring may be different from yours (besides being different from Universal's panels, Seaward itself had different panel wirings.)  It's sometimes like a box of chocolates-- for example, the wire color can change from the panel to the harness to the engine (handy!) And colors used have varied from one harness to another.

-k
« Last Edit: January 29, 2019, 08:44:25 AM by KWKloeber »
Logged
Twenty years from now you'll be more disappointed by the things you didn't do, than by the ones you did.
So throw off the bowlines.  Sail away from the safe harbor.  Catch the tradewinds in your sails.
Explore.  Dream.  Discover.   -Mark Twain

Ron Hill

  • Forum - Master Chief Petty Officer of the Navy
  • ********
  • Karma: 52
  • Posts: 6573
    • View Profile
Re: Fuel Pump to Ignition Switch Wiring for M25XP
« Reply #3 on: January 29, 2019, 01:40:46 PM »

Patches : Attach the fuel pump wire to the "ON" pole of you switch.  Your glow plugs should be on the "Momentary" (spring loaded) pole.
If you haven't done it you might want to look at the "glow plug solenoid" upgrade.

A few thoughts
Logged
Ron, Apache #788

Patches

  • Forum - Seaman Apprentice
  • *
  • Karma: 1
  • Posts: 9
    • View Profile
Re: Fuel Pump to Ignition Switch Wiring for M25XP
« Reply #4 on: January 30, 2019, 12:32:27 PM »

Thank you for your replies!  Will attach to the "on" pole of the switch where the panel feed (red #10) wire connects.
Logged
Pages: [1]   Go Up