I’m trying to locate the dc ground buss behind the helm area on my 1990 Gulfstream. The wire diagram for my model and year doesn’t show where all the ground (dc negative) wires from all the 12v components all connect together. There are some on the accessories fuse block under the helm, for what’s being used on the fuse block. Has anyone found where they all tie into the negative ground wire that runs back to the batteries?
1990 Gulfstream dc ground buss location??
- Thread starter J.Wisch
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SkunkBoat
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This is based on other models but...
from the main stud on the neg bus on the fuse block follow the 10awg black wire to the Neg terminal bus (if there is one). There should be a 6 awg black wire on that as well as other 10awg black wires from things like macerator and refrigerator.
The Neg and Pos terminal bus tend to be near each other.
It is possible that the 6 awg goes directly to the main neg stud on the fuse block, in which case all of the grounds go there.
I am assuming your model has 6 awg red (from red button breaker) and black feeding forward.
from the main stud on the neg bus on the fuse block follow the 10awg black wire to the Neg terminal bus (if there is one). There should be a 6 awg black wire on that as well as other 10awg black wires from things like macerator and refrigerator.
The Neg and Pos terminal bus tend to be near each other.
It is possible that the 6 awg goes directly to the main neg stud on the fuse block, in which case all of the grounds go there.
I am assuming your model has 6 awg red (from red button breaker) and black feeding forward.
Thanks for the info. So what I have is 10awg black & red back aft at the batteries. The red has the 40amp push button breaker. They go in the pvc tube fwd to the console. The 10awg black branches, one goes to the neg. on the small fuse block, 2nd goes to the Grady switch panel to provide ground to the switch lights, the 3 goes outboard towards the hull and can’t follow where it goes. 10awg is the largest wire Grady used (except battery cables) on my model year. The diagram in the manual shows that. If I get to it tomorrow after work I’m gonna dig deeper and try to follow the black running out towards the hull. I appreciate your help.
The boat is new to me as of last spring, it ran fine all season. What led me to this search, I removed the batteries to clean the transom area. When I disconnect the batteries I realized only the 10awg positive feed to the panel & the positive cable to the battery switch was connected to the battery and the only negative was the one from the outboard. I found the 10awg ground that goes to the console taped and under the battery box. The fact that everything was working this past season leads me to think the ground is being pulled threw the Yamaha harness. Since no other neg ground wire was connected. Someone must have tapped into the Yamaha ground at the key switch. I need to find that wire and remove it and connect the ground properly. Very odd. I work at a boat yard and it has my electrical buddies stumped. It can’t be good for the electrical components in my outboard.
SkunkBoat
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getting ground thruogh the tank ground and the fuel sender and yammie gauges. I bet you had lots of low volt alarms on your electronics.
As a general rule, o splices are made in the sections of harnesses that are in rigging tubes.
Exactly what doesn't work now?
Exactly what doesn't work now?
The engine buzzer would go off randomly on occasion. Every time I checked the engine temp with thermo gun, always cool. The oil reserve tank and main tank were always full. At the time never thought the grounds were going threw the yammie wires. The yammie techs here said a voltage drop could cause the alarm to get triggered. Also, I lost rpm’s randomly, they also said the vst pump may have also lost voltage causing the rpm to drop and come back. Thanks for the input.
Everything was working last season, but the engine alarm went off a few times, each time I checked the temp at the sender on the head and always cool, oil tank was always full. I didn’t know at the time the negative house wire was never connected and taped up until I removed the batteries this winter for maintenance and cleaning. I just want to wire the boat correctly.
SkunkBoat
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Both tanks are connected to the ground through the sending units to the 3 way switch at the helm and then to the yammie digital multi function display gauge. The ground at the 3 way switch also is the ground for the switch light which ties into the boat ground in the Grady harness.
What model motor is on the boat?
I doubt that the alarm had anything to do with the wires in question
I doubt that the alarm had anything to do with the wires in question
SkunkBoat
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I'm going to ignore the motor alarm for now and concentrate on the wiring.
I understand much older models used 10awg for the House feed. Thats fine for a single GPS/FF and a VHF and a low power stereo and Nav lights.
Once you add Halogen spreaders, a stereo power amp, another mfd, a radar, a macerator you are screwed.
The voltage drop across the wire will cause all kinds of problems.
If it were me I would run 8 or 6 awg duplex up to the helm. Ditch the awful red button breaker for a switchable breaker like Bussman 185 or MRCB
Do you have a hardtop e-box?
Aluminum Tank? Yes?
Your tank should have a 10 awg green & yellow wire (It might be black but its not supposed to be) from a grounding tab to the Neg battery terminal.
If there is a black wire, as well as the pink wire, on the sender it should be attached to ground at the other end.
Your Neg battery terminal should have Neg connections to Motor, House, Tank, and Bilge pump(s) at a minimum.
You need to find things...
I understand much older models used 10awg for the House feed. Thats fine for a single GPS/FF and a VHF and a low power stereo and Nav lights.
Once you add Halogen spreaders, a stereo power amp, another mfd, a radar, a macerator you are screwed.
The voltage drop across the wire will cause all kinds of problems.
If it were me I would run 8 or 6 awg duplex up to the helm. Ditch the awful red button breaker for a switchable breaker like Bussman 185 or MRCB
Do you have a hardtop e-box?
Aluminum Tank? Yes?
Your tank should have a 10 awg green & yellow wire (It might be black but its not supposed to be) from a grounding tab to the Neg battery terminal.
If there is a black wire, as well as the pink wire, on the sender it should be attached to ground at the other end.
Your Neg battery terminal should have Neg connections to Motor, House, Tank, and Bilge pump(s) at a minimum.
You need to find things...
Last edited:
My house feed goes to the Grady panel which has: nav/anchor light, horn, wipers, manual bilge fwd, manual bilge aft, cockpit lights x2, live well and wash pump, fresh, fuel tank gauge selector. Also feeds the fuse accessory block which has fresh water galley pump, cabin lights, and trim tab pump.
Over the winter I added a negative buss bar that the negative cables from both batteries tie into. On the neg buss I have both aluminum fuel tank and fill ground wires (8awg green), bonding wire to my thru-hull valve, transom zinc, engine bracket bonding wire. Start battery has negative cable to outboard. Battery selector switch has engine positive and house feed on the load stud.
I’ll beef up the house feed and ground. The ground will go to the buss bar with the battery negative cables. I’ll move the sending unit grounds to the ground buss at the battery (shorter run ).
no hardtop, radar, flood lights. My electronics are in a dash box: vhf, Ray marine chart plotter, ais, stereo. These have a dedicated feed and ground from the battery switch and neg. (10awg with 30amp fuse on the positive) the electronics have appropriate fuses in the dash box.
Over the winter I added a negative buss bar that the negative cables from both batteries tie into. On the neg buss I have both aluminum fuel tank and fill ground wires (8awg green), bonding wire to my thru-hull valve, transom zinc, engine bracket bonding wire. Start battery has negative cable to outboard. Battery selector switch has engine positive and house feed on the load stud.
I’ll beef up the house feed and ground. The ground will go to the buss bar with the battery negative cables. I’ll move the sending unit grounds to the ground buss at the battery (shorter run ).
no hardtop, radar, flood lights. My electronics are in a dash box: vhf, Ray marine chart plotter, ais, stereo. These have a dedicated feed and ground from the battery switch and neg. (10awg with 30amp fuse on the positive) the electronics have appropriate fuses in the dash box.
SkunkBoat
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Oh ok. You have another home run pos & neg and fuse panel just for electronics. That explains why running a pump or tabs didn't cause low volt errors.
It was just by coincidence I ran the dedicated feed and fuse panel for my electronics, (The radio and fish finder that came with the boat were junk and it was a rats nest in the dash box. Replaced with new gear and dedicated power) not knowing at the time the house ground wasn’t hooked up. My live well/ wash down pump was in op when I got the boat last year. I have a new pump installed now . My wipers were in op last year too. If those had been working I may have noticed something was not right since those draw higher amps.
Skunk boat and Seasick,
thank you for your information and input. I greatly appreciated it. I am just about finished changing out some of the wiring, including proper ground wire size. Everything appears to be working now. Hopefully I’ll get her launched by mid-late April. Just in time for squid. Have a great season. Thanks again.