Notices

EFI to Carb Wiring

Thread Tools
 
Old 11-17-2018 | 12:20 PM
  #1  
Thread Starter
Registered
 
Joined: Sep 2013
Posts: 26
Likes: 0
From: Jacksonville, FL
Default EFI to Carb Wiring

Apologize if this topic has been beaten to death previously.

Getting ready to remove a 502mpi from the boat and replace with a carbed 555. Will any of the current wiring harness work ? Or will a separate harness be needed with the conversion from efi to carb ?
duplera is offline  
Reply
Old 11-17-2018 | 12:56 PM
  #2  
Registered
10 Year Member
 
Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
Default

You’ll just have a bunch of wires and plugs left over. It works but just unsightly. I made a bracket to mount the gizmos to the back of the engine from port side header but had a lot of left over wire that needed shortened and at that point I wish that I just gotten a carb harness from CP.

https://www.cpperformance.com/p-1323...e-harness.aspx

All you need is the water temp, oil pressure, choke, and whatever else you want to add. The ignition wire wasn’t large enough to supply my DUI ignition so I ran that wire to a relay for a heavy
gauge wire.
Baja Rooster is offline  
Reply
Old 11-17-2018 | 03:41 PM
  #3  
Registered
15 Year Member
 
Joined: Nov 2009
Posts: 4,198
Likes: 500
From: KY
Default

Agree, can use it, and disconnect the EFI part from the engine harness, or get one of these and make a custom install, sell the harness you have on the swap shop maybe

https://www.michiganmotorz.com/custo...ss-p-4508.html
AllDodge is offline  
Reply
Old 11-17-2018 | 11:11 PM
  #4  
BUP
Banned
 
Joined: Jul 2011
Posts: 9,594
Likes: 45
From: Ft. Worth TX
Default

got some of the same and cheaper priced.
BUP is offline  
Reply
Old 11-18-2018 | 10:37 AM
  #5  
Registered
 
Joined: Jul 2017
Posts: 32
Likes: 0
From: Harrington DE
Default

I was able to separate mine easily.
Hot Rod 29 is offline  
Reply
Old 11-18-2018 | 10:50 AM
  #6  
F-2 Speedy's Avatar
Platinum Member
Community Builder
10 Year Member
Platinum Member
 
Joined: May 2012
Posts: 11,425
Likes: 3,953
From: Midwest & T-Rock
Default

Originally Posted by AllDodge
Agree, can use it, and disconnect the EFI part from the engine harness, or get one of these and make a custom install, sell the harness you have on the swap shop maybe

custom-mercruiser-style-engine-harness-p-4508.html
I've used these before, but their not complete you will need to reuse the large orange wire from the alternator to the starter battery feed, but their pretty well made.
F-2 Speedy is offline  
Reply
Old 11-18-2018 | 11:49 AM
  #7  
BUP
Banned
 
Joined: Jul 2011
Posts: 9,594
Likes: 45
From: Ft. Worth TX
Default

if stock engine set up and drive set up -- outdrive gear lube bottle alarm as well
BUP is offline  
Reply
Old 11-18-2018 | 11:51 AM
  #8  
BUP
Banned
 
Joined: Jul 2011
Posts: 9,594
Likes: 45
From: Ft. Worth TX
Default

correct about the alternator wire as its a bigger gauge wire as well.
BUP is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.