An unknown wire

Southern Pirate

Active Member
Nov 17, 2019
107
Boat Info
2005 sea ray 270 amberjack
Engines
5.7 Mercruiser w/Bravo III Drive
I pulled my 5.7 MPI motor from my 2005 Sea Ray Amberjack. When I did, I thought that I had disconnected and labeled all the wires. After pulling the motor, I noticed a red wire (looks like an 8 gauge) next to where the started would have been, with the terminal broken off. It has a wire cover on it and it comes from the starboard rear of the boat. It is fasten to one of the stringers before it heads to the motor. I looked and looked and have yet to determine where the wire goes. I tried to trace the wire but have so far been unable to find what it goes to. Can anybody give me some insight? Does it connect to the starter because that is what the length and position suggests.
 
Are you saying you pulled the engine and forgot to undo the big red lead going to the starter? Or this was already disconnected and you just noticed it now that the engine is out?

This is the only pic I could find one one of my starters. In the bottom right of the pic, there's a giant red lead going to the starter, then another smaller one. From the looks of it, that's 8 or 10ga but can't be sure.

upload_2022-4-28_7-14-43.png
 
There could be 2 big red wires in that area... one to power the starter, and one to power the DC breaker panel. The one for the DC panel will usually have an inline fuse... like 50A.
 
Are you saying you pulled the engine and forgot to undo the big red lead going to the starter? Or this was already disconnected and you just noticed it now that the engine is out?

This is the only pic I could find one one of my starters. In the bottom right of the pic, there's a giant red lead going to the starter, then another smaller one. From the looks of it, that's 8 or 10ga but can't be sure.

View attachment 125313
That's it. The smaller wire. I disconnected the 4/0 wire but did not see the smaller wire until the motor was out of the boat. It looks like it connects with the main battery lead. Thank you so much
 
That's the wire that goes to the 50 amp breaker and should be connected to the 90 amp fuse at the starter.
 
There may or may not be the 90A fuse at the starter for this wire.
The fuse was added by Mercruiser on the newer models, may not be on a 2005
 
There may or may not be the 90A fuse at the starter for this wire.
The fuse was added by Mercruiser on the newer models, may not be on a 2005
I have the fuse, just moved it to a buss
That's the wire that goes to the 50 amp breaker and should be connected to the 90 amp fuse at the starter.
 
well...
Keep in mind the reason Mercruiser added that 90A fuse at the starter is because the 8AWG was unprotected and cant handle more than 80-90 amp. If it shorts (chaffing) between the starter and the 50A breaker or the alternator it will smoke. It was considered a fire risk and they added the circuit protection
 
well...
Keep in mind the reason Mercruiser added that 90A fuse at the starter is because the 8AWG was unprotected and cant handle more than 80-90 amp. If it shorts (chaffing) between the starter and the 50A breaker or the alternator it will smoke. It was considered a fire risk and they added the circuit protection
Good point, I will move the wire to the fuse. I don't see any reason to keep it on the starter.
 

Forum statistics

Threads
112,948
Messages
1,422,804
Members
60,930
Latest member
Ebrown69
Back
Top