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Fuel pump wiring question

D

Dieter

Advanced Contributor
To all,

several of you have helped this project move along in the past so thanks for your help thus far.

I am am in the process of of swapping out a cracked block 4.3(OM491962- 2bbl) with a 5.0 partial engine from Michigan Motorz. I'm getting ready to install new engine which I test ran on a pallet already.

During removal I had noted two 2 pin wiring plugs that connected the boat harness to the engine harness and fuel pump in a separate connection than the 10 pin plug. There are pictures attached of these two connections that were located on the intake near the choke on the original mercarb. One is male other is female and are marked M8 and F9. what's making me question my previous notes is that both of these plugs have grey and black wors coming into it, I thought grey was for tach wires not fuel pump power. I traced these wires out with an ohm meters and there is no connection to any of the 10 pins at the engine harness connection, but rather the two grey wires at each plug have continuity.

I ran ran the engine by connecting the fuel pump to a similar 2 pin connector that comes out of the engine harness near the sift interrupt and base timing mode connection. This plug had the yellow and purple wire as shown to power the fuel pump in the wiring Diagram. This is shown in the third photo.

Is is there a connection back to the boat harness for the fuel pump control? The engine ran fine in this configuration? Is this used to allow the fuel pump to be located off the engine in some applications (wire stretcher? ).

For or some reason I can up load the photos now. Will come back with those in another post....

thanks
 
Ok photos got there but first and last are harness connections on the boat harness, middle is connection on the engine harness that I hooked fuel pump to and appears to be working. Thanks in andvance for your help!
 
Boat is a 2004 Sea Ray 200 sport - do you need boat serial? . Engine was a June 2003 build date. Thanks for your help.
 
No

It is easier to look up certain info with the year of the boat vs serial number.

I looked and I don't seem to have the schematics for that year motor.

If someone has this info please share and maybe where to locate the schematics.
 
here is what I found

two posts containing the schematic and wiring descriptions

Schematic..........
 
Now the manual I used was for TKS carbed motors.

Was your 4.3 a TKS carbed motor?

Oh and the serial number you gave in your first post is for the outdrive not the motor..........
 
Yeah fat fingered the serial number... engine is OM694685. June 2003 build date non- TKS mercarb.

I have the fuel pump hooked up to what would be 16 on this harness but on mine it is right next to the two bullet connections for the shift interrupt and the single bullet for base timing mode.


The M8 and F9 plugs were on the boat harness not the engine harness, they originally came across the intake from the port rear of the engine. My disassembly notes have them plugged into he engine harness and fuel pump but I'm doubting my notes as the wire is gray and the fuel pump works on the test stand...

Thanks
 
OK

Need additional information.

1. what wiring harness was in the boat when you bought it? The one you are using now or a different one?

there is a chance someone changed the carb before you bought it from TKS to a mercarb. Word has it the TKS carbs SUCK!

The wire harness you appear to have now, has to be from a TKS system as my schematic shows other wise I would assume you would have a standard carbed older type wiring harness.

A non TKS wiring harness would not have those GM style weather tight connectors.

How was the fuel pump wires on V6? try to be specific....

If it had those connectors then I would say it was originally a TKS system.

I myself have never had the pleasure to work on one so I can not say for sure......

Also there is no grey and black connector in that schematic..........
 
I am trying to upload larger pics.......may or may not work......this dam uploader sucks!!

Middle pic is the top of schematic
left pic is the middle of the schematic
 
Kghost thanks for the replies.

1. Harness is the original one and is unmolested, no mods or splices. Engine harness should be part # 84-862163T02. I doubt any one replaced the carb as the mercarb still had the tamper cover on the idle mixture and boat only had 38'hrs on it. Intake and carb were removed before I bought it to confirm that block was cracked, but all wires,throttle bracket with solenoid, and distributor were still on engine just pushed out of the way a little.

Wiring I have is is different than schematic you posted
http://www.boatfix.com/merc/techbk/96/96hgd4.pdf

page 4D-4 has the harness I have(4.3 T Bolt V no knock control)

If my dissasembly notes are correct fuel pump was connected as in the photos I found on line - http://www.imagebam.com/image/334137253182237

This is not my engine but found online red arrow pointing to shift interrupt bracket - note by point of arrow there is a folded up harness coming from the boat harness. This is exactly how my boat is. That is why you don't see a grey wire on engine harness- it is on the boat harness not the engine. See how the one connector plugs into the engine harness where the shift interrupt wires and base timing plug come out? Other plug in this harness goes to the fuel pump.

http://www.imagebam.com/image/12a7ba253182241

another photo from same boat, note how there is a small harness with just these two two wire connectors in it, you can see engine harness below with purple yellow choke wire. This must take the fuel pump run 12v go to the boat or instrument cluster and come back with the other plug tosupply the fuel pump. One of these plugs is male the other female so no way to mix it up.

bottom line these photos match my notes and memory of when I pulled out the V6, but this didn't jive with the diagram from boat fix above and grey color on boat harness made me question my notes and memory. Just not sure why this is set up this way. Who supplies the helm harness to sea ray Mercruiser? I can't find a helm harness diagram anywhere.

Hope fully this makes sense to you and someone knows why this is wired this way.

Thanks again for your help.
 
Ok

The schematic on that page is what I have also in a manual.

The schematic does NOT show the water tight connectors........that is what threw me off............I have not had the fortune to work on a 2004 yet.

Most of my work still revolves around 1980-2000 ish.........................there are so many in that year rang around me.......even mine.

Manual 25 is the one for your boat.

The schematics for the EFI models all show a grey wire for the fuel pump and it goes into a relay.

DO you have relays?

It appears to me that you have a mid stream change wiring harness. It is designed for both pre and post water tight/efi connectors......

What I would do is use the efi or schematic from the TKS as reference and make sure you know were the wires are actually going and match up with one of the schematics......
 
Last edited:
Kghost,

Thanks again for your help. What I now find is I'm a schmuck... I looked in the boat owners manual... what I should have done in the first place. I find these two pages of the specific harness for my boat (assumed helm harness was Mercuiser supply as well). View attachment 12888View attachment 12887

I find the two connections (labeled M8 and F9 on boat harness) detailed. It shows these two connections bringing the fuel pump power supply in series with a set of contacts (aka a relay) in the electric fuel shut off valve. Valve not open = pump no run, not a bad idea. This is why the mercruiser harness is correct and the motor runs and why my notes show these wires from disassembly, and why you don't see it on every 4.3 with an electric fuel pump...

My experience too is on older boats- until this my newest one is a 1991 with a 3.0 about as simple as it gets. This does make me long for the 1956 Evinrude 5.5 my grandfather gave me - start in any gear and a pressurized fuel tank...

Thanks for your help working through this!
 
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