Logo

1999 150HP Merc EFI wiring

Jolendd

New member
Have a 1999 Merc 150hp EFI outboard that overheated last year because of pump impeller failure, I have been asked to help repair it. It appears it has melted/shorted out the wiring harness on the engine, I believe the harness should be replaced, any suggestions of the next step, ? Repair harness? replace harness? Are they available? Is cost prohibitive of replacement over repair?

Thanks, Johnny
 
Re: 150HP Merc EFI wiring

That is a result of what we would call " severe overheat "----------------the head gaskets should be replaced as well.--Do a compression test. Then pull the cylinderheads.--Inspect cylinders.----------It would be silly to spend a lot of time and money on wiring, and then find out other major problems..
 
Re: 150HP Merc EFI wiring

I have not actually seen the motor yet? After the impeller failure, it pump was repaired/changed, approx 3hrs of "operation" later there was smoke and fire that was extinguished with a fire ext. So I believe ? it was not a severe overheat, I agree, a very thorough inspection needs to be done, before one "wastes" good money!! Thanks for info = But if it is only a wiring issue, original question applies, wiring harness? fix/replace?
 
Re: 150HP Merc EFI wiring

Look up the price of the wiring harness and perhaps other plastic parts , and then a decision can be made.
 
Re: 150HP Merc EFI wiring

Thanks, my question is, is a wiring harness a captive Merc part? aftermarket? Just call local dealer? I am new to boats but been licenced HD mechanic for 30+ years.......I will call Merc dealer, looking for other sources, I suspect the harness will be discontinued.
 
Re: 150HP Merc EFI wiring

84-826730A4 HARNESS ASSY, The wire harness looks to be an active part still, MSRP: $164.34 with many still available. You will need the engine serial number so that you can order the correct parts for your engine.??? If you would like some help with finding your parts, You could post the serial number here. Your Mercury service manual part number is going to be 90-824052R2 or the newest manual out is part number 90-824052R3
Sorry my post is all ran together as one, For some reason the forums computer system does it automatically now.
 
Re: 150HP Merc EFI wiring

Jolendd,

We have aftermarket engine wiring harnesses here. Be sure to click on the "next page" link when you get there.

84-826730A4 is available as boat_tech mentions above.

Boat_tech:
Sorry my post is all ran together as one, For some reason the forums computer system does it automatically now.
The text box that you enter your message/reply into should work like any editor or word processor. You should be able to use the enter button to create new lines and spaces. Let me know if you have any problems and I will try to help.

Thanks.
 
Re: 150HP Merc EFI wiring

Boat_tech:
The text box that you enter your message/reply into should work like any editor or word processor. You should be able to use the enter button to create new lines and spaces. Let me know if you have any problems and I will try to help.

Thanks.[/QUOTE]Hi there, Yes I am aware of hitting enter to space it all out. It just was not working at the time you see above no matter what I tried to do to fix it.

But now as you can see everything seems to be in working order at this time, So thank you for the offer to help me out.

Thanks.
 
Back
Top