starter wiring hookup SAE J1171

[joebud45]

I have a 1976 120 hp OMC- Pontoon boat that was recently rewired and having a significant battery drain
with everything off. While running through a wiring diagram I obtained on this site AFTER the boat was rewired, I discovered that the battery drain could be related to the final destination of a 10 gauge
black wire that was connected to the postive 3/8" brass stud on the starting selenoid and, from there ran to the helm and was connected to the negative side of a buss bar. In addition to the black wire
described above, there was a 10 gauge orange wire from the alternator, the 4 gauge red wire from the battery and a 10 gauge red wire that connected to the slave selenoid on the left side post. All of the red wires described above are attached to the same 3/8" brass stud as the" suspect" black wire.A 10 gauge black wire ran from a 1/4" silver stud on the right side of the selenoid to the right side post on the slave selenoid.

The original wiring harness at the helm not include the 10 gauge black wire. There is a 10 gauge brown
wire coming out of the harness at the helm that also fed to the negative side of the buss bar. I disconnected the 10 gauge black wire at the negative buss, left the brown connected and, everything
seems to be working OK although I am still using at quick screw off disconnect to the postive battery
terminal when I leave the boat unattended for any length of time.

I am using a new deep cycle marine battery with 875 cold cranking amps and 125 reserve amps. using a
1.5 amp trickle charger to maintain battery when boat not is use. Any help with the starter and buss
wiring hook up will be greatly appreciated.

Joe Bud45

With respect to the buss bar, the 10 gauge red wire runs from the bar to the "B" on the ignition switch.
The orange 10 gauge wire from the wiring harness at the helm is connected to the positive buss bar.
I am assuming it is originating from the alternator and is connected to the " I" on the ignition switch.
A 10 gauge dark blue wire runs from the " s" on the ignition switch to the top post of the slave selenoid.
I have since learned that this was also wired incorrectly since the safety neutral switch was bypassed
allowing the boat to be cranked while in gear.

The buss bar is feeding a 35 amp 7 position fused panel for horn, bilge pump, blower,running lights,
and radio. The buss bar was also supplying power to the ignition switch.

 

[Silvertip]

Re: starter wiring hookup SAE J1171

If there is really a black #10 wire running from the large post on the starter solenoid to the NEG buss at the helm, it is strange that you still have a pontoon boat. If that large post is the one that has the POS battery cable connected to it then the #10 wire does NOT go to the NEG buss. The NEG buss goes back to the NEG post on the battery so you have a direct short and should really have smoke and fire. Next -- is there more than one wire on the "B" terminal of the ignition switch? That terminal should have only the +12 volt feed from the engine via the engine to control box/helm harness. Ignition switches are not intended to power the entire boat electrical system.

 

[joebud45]

Re: starter wiring hookup SAE J1171

Silvertip, Thanks for the input. The # 4 red wire runs from the battery to the large post on
the starter selenoid. The # 4 black wire runs from the battery and is grounded to the engine.
What I was referring to is a # 10 wire that appears to be attached to the same large post
on the selenoid and runs to the helm where it was connected to the negative buss. I had been having a serious battery drain, losing as much as 3 volts over 3-4 hours when boat was
in port with nothing on. Bubba 1235 was kind enough to send me a wiring diagram after the
boat was rewired by a mechanic who claimed he knew how to wire a boat and obviously did not. It was while I was tracing out the schematic did I see several suspect issues.

Relative to your point about smoke and fire, right after I got the boat back from the "rewiring
mechanic" I was having some starting issues and the timing was screwed up. While trying to
start the boat several times, I noticed smoke coming off the #4 black wire at the battery.
Both battery leads were very hot to the touch. I disconnected the battery and called a
more competent mechanic. He said the starter had shorted out and he replaced the starter.
For some unexpalined reason, he never checked to see where the # 10 black wire on the
selenoid was going, which in fact, was wired to the Neg Buss.

With the info you have provided, I will check everything out this weekend. Thanks for your help. I was reading several other threads ealier today about console wiring and they provided
some excellent information. Thanks! Joebud45

 

[fucawi]

Re: starter wiring hookup SAE J1171

I think you are going about this the wrong way . with every thing off you need an ammeter between battery negative and the bat neg cable . This will show your drain . For every 1/2 A load you have about 6 watts ..so work out the load and think what this could be ....maybe your alternator rotor is permanently energised if its abot 3 -4 A .....go around disconneting lives /fuses until you get it to drop to zero to find the fault

 

[joebud45]

Re: starter wiring hookup SAE J1171

Fucawi, Thanks for the tip. I am pretty much a novice on the electrical side and I really appreciate the advice. This forum has really helped me learn a lot more. Thanks, Joebud45.

 

[Silvertip]

Re: starter wiring hookup SAE J1171

I hate to keep after this but here is what you are describing:

What I was referring to is a # 10 wire that appears to be attached to the same large post
on the selenoid and runs to the helm where it was connected to the negative buss.

Which post on the starter solenoid is this #10 wire connected to? There are only two large posts. One has the red POSITIVE batery cable connected to it. The other goes to the starter. If that #10 wire is on the POSITIVE side of the starter solenoid and then goes to the NEG buss at the helm, that is a direct short. So clarify please -- not using the term "same post".. This is also important since you earlier said disconnecting this wire makes everything work ok (and obviously it would if it is indeed connected as you describe).

 

[joebud45]

Re: starter wiring hookup SAE J1171

Sorry for the confusion. There is a #4 red wire from the battery attached to the positive
post on the selenoid. This selenoid is attached to the starter.Also attached to the Pos. post on the selenoid is a #10 orange wire from the alternator and 2 # 10 red wires. One of these #10 red wires is attached to the positive side of a separate "slave selenoid". The other leads to the wiring harness that appears to go to the helm to a large connector and exits the connector as a #10 orange wire and is attached to the Positive Buss. A single #10 red wire leads from the Positive Buss to the " B" on the ignition switch. Now, the #10 Black wire is ALSO attached to the Postive post on the starter selenoid and was connected to the NEG. Buss. A #10 black wire is connected to the silver NEG post on the starter selenoid and runs to the Neg. post on the "slave" selenoid. As far as the actual stater is concerned, I can see that there are 2 threaded bolt studs on the fron of the starter with nothing connected to them.

I have only used the boat a couple of times for 30 minute cruises since it was rewired and I noticed that three of my new 35 amp fuse panel lighted rocker panel switches were not working. I disconnected the # 10 black wire from the NEG Buss and installed a new fuse panel which appears to be working fine.

What was confusing to me was there was a # 10 black wire in the harness from the engine
leading to the large connector at the helm, but there was no #10 black wire or a black
wire of any size exiting the connector to go the the Neg. Buss. Only a #10 brown wire
which I connected to the NEG Buss. I did not see any Brown wires listed on the wiring schematic and I am thinking that the brown wire coming out of the connector at the helm was a "faded" black wire. After all, the boat and the original wiring harness is 33 years old.

I will use an amp meter as soon as I can get back to the boat to see if just disconnecting
the suspect #10 black wire from the NEG Buss was the cause of the battery drain or if there
are other issues. Hope I have not confused you and I appreciate the help. Joebud45

 

[Silvertip]

Re: starter wiring hookup SAE J1171

That black #10 wire should definitely NOT be connected as you describe. You cannot have a direct +12 volt battery connection to the NEGATIVE buss at the helm which is exactly as you describe. Since that also represents an unprotected circuit I don't understand why there isn't a fire although you did mention some very hot wires previously. Remove that wire. It is not needed. The ground buss at the helm should go directly back to the NEG terminal on the battery. An alternate would be to the engine block via the engine harness but that leaves too many potential points of failure.

 

[joebud45]

Re: starter wiring hookup SAE J1171

Silvertip, Many thanks for your persistence and aid in diagnosing my problem. Will let you
know how everything works out after I get back to the boat next week. Joebud45