MK1 fuel pump wiring

[Pete G]

I replaced the gauges and wiring harness to the engine.  I'm not sure where the fuel pump should be connected.  Help!

Pete

[KWKloeber]

More info

Which engine does she have
What do you mean "replaced" it? With what, from what source.  Is it a custom made harness or a hunk of wire between two points.

Picture of what you had before you replaced whatever you replaced?

[Pete G]

The boat had the original wiring harness and the PO hadn't done the critical upgrade.  I bought the replacement from CatalinaDirect.  The previous was the standard RV connector, but the fuel pump isn't part of that harness, in either case.  In the original, the fuel pump connects to the ammeter, which I replaced with a voltmeter.

[KWKloeber]

To say the best/easiest way to wire the pump, need to know: Did you butt crimp the expensive hunks of wire from CD onto your engine harness, or did you use the non-ABYC compliment terminal strip that CD also sells?

[High Current]

Did you crimp the expensive hunks of wire from CD to your engine harness, or did you use thr non-ABYC compliment terminal strip that CD sells?

That burns almost as much as the original harness...

——-

For the M25XP, the fuel pump should come on with the key switch.

In the original diagram, I believe battery is red and alternator is orange; both are connected via the ammeter and go to "B" on the key switch.  That means "A" / purple is the switched side and the fuel pump should be connected to it.

You should be able to trace the wire from the pump to figure out which end it terminates at.

[KWKloeber]

Did you crimp the expensive hunks of wire from CD to your engine harness, or did you use thr non-ABYC compliment terminal strip that CD sells?

That burns almost as much as the original harness...

——-

For the M25XP, the fuel pump should come on with the key switch.

In the original diagram, I believe battery is red and alternator is orange; both are connected via the ammeter and go to "B" on the key switch.  That means "A" / purple is the switched side and the fuel pump should be connected to it.

You should be able to trace the wire from the pump to figure out which end it terminates at.

The easiest way to hook up the Facet depends on the answer to my question.

[Pete G]

Just to be clear, the fuel pump wiring is not part of the replacement harness.  It has ring connectors and the positive and negative wires, fwiw. 

For the replacement, I used ring connectors and replaced the wiring from the engine to the new gauges also using ring connectors.  All of the gauges are working correctly.   

[Ron Hill]

Pete : From what I've seen the electric lift pump for the M25XP engine is wired direct to the "ON pole" of the key switch!!!

Mine was NOT wired thru the trailer connector, but a separate wire direct from the Facit pump to the key switch.

A thought

[KWKloeber]

Just to be clear, the fuel pump wiring is not part of the replacement harness.  It has ring connectors and the positive and negative wires, fwiw. 

For the replacement, I used ring connectors and replaced the wiring from the engine to the new gauges also using ring connectors.  All of the gauges are working correctly.   

Pete

Ok so you didn't just eliminate the RV plugs and run new wire between where they were and use thr CD terminal strip. Good!

The wire run to the fuel pump was redundant.  All is needed is a 12v supply when the key is on.   Yes, you can run it from the panel (any 12v terminal when the key is on, such as the key switch "I" terminal, or any "+" terminal on any gauge or the tach.   

However, being redundsng, I do not do that on my new harnesses. I tap the Alternator Excite circuit in the engine compartment and run it to the pump.

Depending on your alternator you can do this a few ways:

1) Make a special Y plug or pigtail that splits back to the fuel pump from where the excite (purple) wire plugs into the alt regulator wire.

2) If the Alt has a screw terminalfor the excite circuit, run a wire from there to the Facet.

3) Use a yellow butt connector to tap the purple excite wire to power the Facet.

Questions on that just hollar.

(If you had used the CD terminal strip then you could have just put the Facet power wire into the terminal with the excite circuit.)

Ken

[Pete G]

I went with the pigtail option.  I verified that the fuel pump was only turning on with the ignition.  However, I'm not able to get the boat to start.  I removed and cleaned the fuel separator.  I checked that fuel is flowing (and bled the separator).  If I spray starter fluid into the air intake, the boat begins to start, but doesn't run.  The engine cranks well.   

[Jon W]

Did you open the bleed screw slightly to get the air out of the system?

FWIW - a while back I couldn't get my M25XP to start. It ran fine the day before. Turns out that the engine shutdown cable didn't push the lever on the engine back to the engine running position, even though the handle at the engine control panel was pushed completely down. Something to add to your troubleshooting list.

[KWKloeber]

If I spray starter fluid into the air intake

NEVER, EVER, USE STARTER FLUID IN A DIESEL ENGINE
You can bend a rod, crack a piston ring, or blow a hole in the cylinder sleeve.  Besides those things to the engine, it can ruin your day.

[KWKloeber]

Pete

Did you use 1/4" quick-disconnect terminals on the excite wire to mate to the Alt excite plug?

Did you bleed at the injector pump?
Did you bleed at the secondary filter?

Because you messed with the primary filter, one suspect is a vacuum leak there.  Always make sure she starts before messing with anything in the fuel supply train, then you are not chasing shadows wondering what the cause is for a no-start due to fuel.

Very useful to troubleshoot air leak issues in the fuel supply train:
https://groups.io/g/Catalina30/topic/if_you_have_fuel_line/106417680


The XP has (IMO) a stupid bleed system and I have recommended on here before that (IMO) owners should change it to the bleed system as I installed mine.

[Pete G]

I bled at the filter. Will try the injector pump on Friday when I get back to the boat

[Pete G]

FWIW, it wouldn't start before I touched the fuel system.