I just installed a Furuno 1815. Works fine. Except when I toggle my trim tabs. The power surge from this shuts off the furuno radar. Any ideas for a fix? I also notice my chart plotter blips a little when I toggle the trim tabs. But it does not shut down. The trim tabs are standard bennett trim tabs. I'm not sure exactly what model. I am fairly certain the power draw from the trim tabs is causing a big enough loss for the radar to lose enough voltage to shut down.I plan on moving my radar ground to a different post. I may also move the trim tab ground also. I am also wondering if I need larger battery cables? Not sure if that would help or what would help?
Radar Shuts Down When Trim Tabs Activated?
- Thread starter Mark DV
- Start date
I'm not sure what model and year boat you have, but...
First thing would be to go back and check all of your work. From what you've written, it appears this all started after you did the install so the installation is the first suspect. It is highly unlikely there is anything wrong with the tab system - that's standard stuff. Besides, the assumption is that has been working fine for as long as you have had the boat (otherwise you would have mentioned it).
Did you follow the radar's directions for wire sizes? Both to/from the radar and also ensure the supply wires (pos/ground) are sufficient for the amp draw on the supply wire?
Check fuses/breakers for power to wherever you tapped into for the radar. Modern electronics are very voltage sensitive - it sounds like you have a power drop and the radar isn't liking it so it shuts down. It could be a fuse that "appears" good and passes 12V, but not enough amps. It could be old/broken/corroded wiring somewhere along the way (same idea as the fuse).
I have no idea if you need larger battery cables (although unlikely)... what size are they? How many batteries? Again, what boat? What accessories? What engine(s)?
I think if you find the choke point (fuse/wiring/etc) you'll fix your problem.
First thing would be to go back and check all of your work. From what you've written, it appears this all started after you did the install so the installation is the first suspect. It is highly unlikely there is anything wrong with the tab system - that's standard stuff. Besides, the assumption is that has been working fine for as long as you have had the boat (otherwise you would have mentioned it).
Did you follow the radar's directions for wire sizes? Both to/from the radar and also ensure the supply wires (pos/ground) are sufficient for the amp draw on the supply wire?
Check fuses/breakers for power to wherever you tapped into for the radar. Modern electronics are very voltage sensitive - it sounds like you have a power drop and the radar isn't liking it so it shuts down. It could be a fuse that "appears" good and passes 12V, but not enough amps. It could be old/broken/corroded wiring somewhere along the way (same idea as the fuse).
I have no idea if you need larger battery cables (although unlikely)... what size are they? How many batteries? Again, what boat? What accessories? What engine(s)?
I think if you find the choke point (fuse/wiring/etc) you'll fix your problem.
It's not a surge, it is a voltage drop. When the tabs are activated, the current flow will cause a drop. When the drop is more than devices are 'comfortable' with, those devices may shut down or reboot. This is pretty common for MFDs
Troubleshooting depends on whether this is something new or something that has occurred as long as you have owned the vessel'
In addition to the first question about when this started, the next important question is " Have you added any new electrical accessories or equipment that is normally powered on?
Let's assume that no new equipment and the problem is new.
Causes can be low voltage at the source (battery) due to a weak battery. That could be a bad battery of an issue with the charging of the battery
or excessive voltage drop due to more resistance in the wiring and/or connections. The most common cause is a bad or corroded connection and that applies both to the hot (12v) feed and the ground circuit.
Testing for excessive voltage drop is simple in theory but more difficult in practice. The voltage drop by spec for non electronic devices should not exceed 10%. For sensitive electronics usually the mad drop should be 3% or less.
If you take a voltmeter and measure the voltage at the positive terminal of the battery to ground and them measure it at the feed for the radar let's say, the difference should not exceed 3% or a tad more.
Your radar for example may want to see at least 11 volts ( a guess on my part) and if your battery standing (no load) voltage is 12.6v . A 12.6% voltage drop would cause the radar to alarm or reset.
The more common cause of drops are corroded/dirty connections. You should check all battery terminals, the fuse block main connections ( 12v and ground) and the fuse holders if used for the tabs.
Your devices should not reset with a 5% drop so if your standing (motors not running) voltage is 12.5 volts, the voltage at the devices on that circuit should be at least 11.9 volts.
If you are electrically challenged, having someone more experienced will help greatly.
Troubleshooting depends on whether this is something new or something that has occurred as long as you have owned the vessel'
In addition to the first question about when this started, the next important question is " Have you added any new electrical accessories or equipment that is normally powered on?
Let's assume that no new equipment and the problem is new.
Causes can be low voltage at the source (battery) due to a weak battery. That could be a bad battery of an issue with the charging of the battery
or excessive voltage drop due to more resistance in the wiring and/or connections. The most common cause is a bad or corroded connection and that applies both to the hot (12v) feed and the ground circuit.
Testing for excessive voltage drop is simple in theory but more difficult in practice. The voltage drop by spec for non electronic devices should not exceed 10%. For sensitive electronics usually the mad drop should be 3% or less.
If you take a voltmeter and measure the voltage at the positive terminal of the battery to ground and them measure it at the feed for the radar let's say, the difference should not exceed 3% or a tad more.
Your radar for example may want to see at least 11 volts ( a guess on my part) and if your battery standing (no load) voltage is 12.6v . A 12.6% voltage drop would cause the radar to alarm or reset.
The more common cause of drops are corroded/dirty connections. You should check all battery terminals, the fuse block main connections ( 12v and ground) and the fuse holders if used for the tabs.
Your devices should not reset with a 5% drop so if your standing (motors not running) voltage is 12.5 volts, the voltage at the devices on that circuit should be at least 11.9 volts.
If you are electrically challenged, having someone more experienced will help greatly.
Whoa.. I just reread your post and saw the pat about the new MFD. In simple terms, you are drawing more current and that is causing more voltage drop. If you don't have a bad or corroded connection somewhere, it is possible that your accessory feed wiring is undersized. Other rewiring, a fix may be to add a new fed ( 12v and ground) directly from the tab pump to the battery switch. That feed would also need a separate breaker.
Couple answers and details. Boat is a 2006 Grady 208. yamaha f150. I have 2 batteries. (have checked batteries they are functioning properly) All electronics have functioned correctly until I added the radar. This is a new issue. The radar is installed exactly to installation instructions. "In simple terms, you are drawing more current and that is causing more voltage drop. If you don't have a bad or corroded connection somewhere, it is possible that your accessory feed wiring is undersized. " This is what I'm thinking as well. I will check my battery cables this evening for size. I may also try wiring the trim tabs directly to battery and see if I still have the issue. If that resolves the issue I will know where to start.
To have a safe installation, a direct connection to a batter requires a fuse or breaker within 18 inches or so of the battery. This is to prevent a fire should the tab feed short out to ground. Note also that if you connect directly to the battery , the tabs will work the battery switch turned off. That may ir may not be an issue for you .
My concern is that if you are 'overloading' the accessory bus, you may have a similar problem when using other devices like fresh water, incandescent nav lights, or raw water washdown. Even a loud stereo could push you past the acceptable current rating.. It seems that the current draw for that unit is about 3.2 amps max. That isn't a ton of load.
My concern is that if you are 'overloading' the accessory bus, you may have a similar problem when using other devices like fresh water, incandescent nav lights, or raw water washdown. Even a loud stereo could push you past the acceptable current rating.. It seems that the current draw for that unit is about 3.2 amps max. That isn't a ton of load.
Thanks for the extra info. Unless something different from original was done, it's unlikely to be your battery cables, though. Check them just to be sure, I suppose.
17 years old is certainly old enough to have corrosion/connection issues, especially if in salt water. While that could be exacerbating the issue, checking the draw you have from the accessories on the power buss will likely tell you all that you need to know. Increasing that feed size (and it's fuse/breaker, of course) will likely take care of the problem... at least until corrosion (if that's part of the problem) gets worse.
Clean power is key with electronics.
17 years old is certainly old enough to have corrosion/connection issues, especially if in salt water. While that could be exacerbating the issue, checking the draw you have from the accessories on the power buss will likely tell you all that you need to know. Increasing that feed size (and it's fuse/breaker, of course) will likely take care of the problem... at least until corrosion (if that's part of the problem) gets worse.
Clean power is key with electronics.
SkunkBoat
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Its really hard to troubleshoot this without seeing the components and connections. Thats why the manufacturers usually tell you to connect power directly to the battery. It rules out a lot of stuff but its completely impractical.
Not sure about the 20ft gradys setup.
Bigger models have 6AWG feeding terminal blocks under the dash. Some high current items run directly to that with a breaker or inline fuse. There is a 10AWG feed from the terminal block to a blade fuse block. Many 'unswitched" accessories are fed from that. There is also a 10AWG feed to the dashboard switch/breaker panel that has Nav lights, horn, etc.
There is also a long 10AWG feed up to the hardtop fuse block.
Ideally you should have connected radar power directly to the terminal block under the dash using the inline fuse. Also, the black to the ground terminal block. That connects it to 6 gauge wire to the battery.
You definitely should not connect the radar to the hardtop fuse block. That makes it share a long run of 10 gauge wire with everything in the hardtop. That is a recipe for a large voltage drop.
Some guys want to be able to switch the radar power. Its not necessary if the mfd controls the radar and if you shut off power using the battery switch when leaving the boat.
If you feed your radar from the switch panel, it shares the 10 gauge wire with everything on the switch panel. Same problem.
Connecting to the fuse block under the dash has the same problem. The tabs might also be connected there to a 15A fuse?
Those fuse panels should be inspected closely. Often blade connections turn green and cause a voltage drop and heat up enough to melt plastic.
I have replaced both of mine (dash and hardtop) and they were both bad and caused voltage drop problems.
Not sure about the 20ft gradys setup.
Bigger models have 6AWG feeding terminal blocks under the dash. Some high current items run directly to that with a breaker or inline fuse. There is a 10AWG feed from the terminal block to a blade fuse block. Many 'unswitched" accessories are fed from that. There is also a 10AWG feed to the dashboard switch/breaker panel that has Nav lights, horn, etc.
There is also a long 10AWG feed up to the hardtop fuse block.
Ideally you should have connected radar power directly to the terminal block under the dash using the inline fuse. Also, the black to the ground terminal block. That connects it to 6 gauge wire to the battery.
You definitely should not connect the radar to the hardtop fuse block. That makes it share a long run of 10 gauge wire with everything in the hardtop. That is a recipe for a large voltage drop.
Some guys want to be able to switch the radar power. Its not necessary if the mfd controls the radar and if you shut off power using the battery switch when leaving the boat.
If you feed your radar from the switch panel, it shares the 10 gauge wire with everything on the switch panel. Same problem.
Connecting to the fuse block under the dash has the same problem. The tabs might also be connected there to a 15A fuse?
Those fuse panels should be inspected closely. Often blade connections turn green and cause a voltage drop and heat up enough to melt plastic.
I have replaced both of mine (dash and hardtop) and they were both bad and caused voltage drop problems.
I inspected all my grounds. Moved the trim tab and radar grounds to different posts. No luck. I ran the trim tab power cable directly to battery selector switch. No luck. Then I ran trim tab power cable directly to battery selector switch and ran trim tab ground cable directly to battery ground. Everything works fine now. My plan is to run the trim tab power cables permanently this way. With a 20 amp fuse next to battery switch. I believe I have too much running off my fuse box coupled with unseen corrosion issues. Thanks for all the advice. Any more advice would always be appreciated.
Fishtales
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Do you have other electrical items that you can switch on/off besides that tabs? Sure sounds like a voltage droop issue but hard to capture unless you have an oscope. Do you have multiple banks of power on the boat to assist in isolation?
Sounds like a good plan. I would confirm that a 20 amp fuse ( use a circuit breaker) is enough for the stall current draw ( the max current the pump will draw when kept running after the tabs are either fully retracted or fully deployed. 20 may be fine, I am just nor sure.
Beyond A Wake
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If you are hauling the boat or storing in a rack make sure the trim tabs retract when ignition is turned off. I don't know if your boat is equipped with the auto retract but in case it is, note that function.
I ran a load test today. Load test at both batteries is good. Load test at my Blue Sea Fuse box fails. The ground wire at the fuse box is smaller than the positive wire. I dont believe this is helping anything. Im not sure if this is the actual issue. My radar positive lead is run through my switch panel. I wanted to be able to toggle the radar on/off after hearing the unit does draw power when powered off. I am using the ground bus bar for radar. See pic. note. the blank 20 amp is where the trim tab was connected.
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boat wiring.jpg
The fact that the negative wire is a smaller gouge is not necessarily a problem as long as it is of sufficient size to meet the voltage drop specs. Assuming your accessory breaker aft near the battery switch is 30 amp, you can look up the wire size needed to met the 3% voltage drop for electronics. For other things like pumps, 10% is OK but if the conductors are carrying loads for mixed types as it would be in your boat, size using the 3% drop.
You also need to know the total round trip distance for the circuit. In your case that is the distance for the 12V to the fuse block added to the distance back from the fuse block to the battery negative. I will also assume that for your hull, that distance is 25 feet.
Using those parameters, you wire should be 6 gauge or larger..
It is possible that the boat was designed for a typical draw than the breaker size, If the cable used was smaller, say 8 gauge, to meet the 3% drop, the maximum amperage draw is 15 amps.
Sounds like a ground issue, not so much a supply issue. Add a new/second ground to the bus under the dash.
SkunkBoat
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From the picture looks like you don't have a Pos terminal bus. They ran the 6 gauge House + feed directly to the fuse panel. I am assuming the 6 gauge House Neg feed goes to the ground bus on the end we can't see.
You connected the radar ground to the ground terminal bus(not the fuse panel ground...correct?) so unless there is a problem with the House ground connection to the battery, you have ruled out the ground as the radar problem.
That orange 10 gauge on the main fuse panel Pos lug looks like the feed to the dash switches (yes?). You are feeding the radar switch from the switch panel Pos bus (a bunch of jumpers on the switches).
My guess is there are a lot of green corroded connections...or loose connections. They are notorious for gremlins....The more you twist the switch panel around to look at it, the worse it gets.
I replaced my switch panel with a new pre-wired one from New Wire. One of the best "just pay my money and get it done" projects I've done on this 20 year old boat. Gremlins are dead.
I would try temporarily connecting the radar Pos directly to the House Pos at the fuse panel and see if you still have problems. That will at least point you in the right direction.
Even though it is not the cause of this problem, IMO...for S&G....get a new fuse panel. Start fresh. Same in the hardtop.
I'm not convinced you need to switch the radar power. I see that it is a stand-alone unit. If you turn it off, its power draw is no more than any other electronic unit you have.
NMEA2k is on all the time (unles you switched that). If you turn off the battery switch or have a switchable breaker on the house feed, you can shut everything (except bilge pumps) when you are off the boat.
You connected the radar ground to the ground terminal bus(not the fuse panel ground...correct?) so unless there is a problem with the House ground connection to the battery, you have ruled out the ground as the radar problem.
That orange 10 gauge on the main fuse panel Pos lug looks like the feed to the dash switches (yes?). You are feeding the radar switch from the switch panel Pos bus (a bunch of jumpers on the switches).
My guess is there are a lot of green corroded connections...or loose connections. They are notorious for gremlins....The more you twist the switch panel around to look at it, the worse it gets.
I replaced my switch panel with a new pre-wired one from New Wire. One of the best "just pay my money and get it done" projects I've done on this 20 year old boat. Gremlins are dead.
I would try temporarily connecting the radar Pos directly to the House Pos at the fuse panel and see if you still have problems. That will at least point you in the right direction.
Even though it is not the cause of this problem, IMO...for S&G....get a new fuse panel. Start fresh. Same in the hardtop.
I'm not convinced you need to switch the radar power. I see that it is a stand-alone unit. If you turn it off, its power draw is no more than any other electronic unit you have.
NMEA2k is on all the time (unles you switched that). If you turn off the battery switch or have a switchable breaker on the house feed, you can shut everything (except bilge pumps) when you are off the boat.
Ran some voltage drops at the fuse box with a multimeter. Here is what I have. Any thoughts?
12.7 volts drops to 8.3 when trim tabs engage
12.7 drops to 12.5 with Garmin chartplotter on
12.7 drops to 12.2 with radar display on. Then drops to 11.8 with radar running. (another note is when I turn radar switch panel on voltage drops from 12.7 to 12.42 this is without powering on the radar display)
12.7 volts drops to 8.3 when trim tabs engage
12.7 drops to 12.5 with Garmin chartplotter on
12.7 drops to 12.2 with radar display on. Then drops to 11.8 with radar running. (another note is when I turn radar switch panel on voltage drops from 12.7 to 12.42 this is without powering on the radar display)
SkunkBoat
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you previously said "....Then I ran trim tab power cable directly to battery selector switch and ran trim tab ground cable directly to battery ground. Everything works fine now. My plan is to run the trim tab power cables permanently this way...."
Is the trim tab still direct to battery? It was OK and now its not? Whats the voltage at the battery when you trim?
Thats a big drop for tabs. Doesn't that cause your garmin and vhf to shut down too?
When you start your motor does the radar/garmin blip?
I am back to suspecting a missing ground somewhere.
Are you sure the ground terminal bus pictured is connected to the battery with a 6 awg black wire? And the battery neg terminals are jumpered together with 2 AWG black wire?
If the House ground is bad or missing often there is still some small wire connection to battery ground thru other ground wires on the terminal bus (fuel sender, bilge pump, fuel tank bonding, motor cabling/gauges)
It works OK with minimal things running but the more total current thru the small wire, the higher the drop across the wire
i'm not sure what is connected to the fuse panel ground vs the ground terminal bus that is pictured.
IMO, I would replaced the black 10awg wire jumper from fuse panel ground to the terminal bus with a 6awg black wire (or at least double up the 10 awg jumper).
I would be in the "isolate" mode of troubleshooting. Test the trim directly to a battery without any other connections and see what the battery voltage drops to.
Try running a temporary long 10awg (or greater )jumper from the fuse panel, across the deck to the battery, and test. Do that on the Ground side and then on the Pos side.
Skunkboat. Sorry for the confusion. This test was done with trim tabs connected back to fuse box in there original position. I ran them directly off the battery temporarily. The test was not done with them connected directly to battery. Couple answers to questions. Garmin does blip when I start engine. It does not shut down. I am not sure of this and highly suspect something is wrong with grounding.
"
I am back to suspecting a missing ground somewhere.
Are you sure the ground terminal bus pictured is connected to the battery with a 6 awg black wire? And the battery neg terminals are jumpered together with 2 AWG black wire? "
The temp ground is a great idea. Thank you
"
I am back to suspecting a missing ground somewhere.
Are you sure the ground terminal bus pictured is connected to the battery with a 6 awg black wire? And the battery neg terminals are jumpered together with 2 AWG black wire? "
The temp ground is a great idea. Thank you