ignition protection

dogdoc

dogdoc

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Since the new 250 Zukes if you start the engines with the Raymarine MFD, Autopilot on they often go crazy. Lose GPS fix and have to be shut down and wait for them to come back. This sometimes happens when drifting or bottom fishing. Asked the shop when they hung engines to wire to prevent this but obviously they did not. These devices are supplied by a common 12v source which supplies nothing else. Is there a simple way to prevent this from happening at this 12v source?
 
house and start are separated with exception of acr's. as you may be aware the df250 lacks the aux charge wire commonly found elsewhere. prior to hanging the new engines i redid the battery compartment and added 2 blue seas acr's. i provided the shop with a wire from the ignition start interrupt but they said they could not make it work. boat is currently on a trailer so now is a good time to return to this problem. can you give some specifics on wiring. i have the wire connected to the si lugs but coiled up at the helm.
thanks
 
i may be wrong but i also remember them saying cutting wire at the switch may void warranty?
 
The issue is voltage drop on the accessory buss. That can be related to many things, the more common being weak batteries (a load test can confirm), Confirm that you have the correct type and capacity batteries.
bad or corroded connections in the connections, fuse receptacles, battery switch and all common ground circuits.
Finally, your accesory laods may be greater than the wiring was sized for. Electronics should be connected by circuits that are rated for 3% or less voltage drop whereas other loads like pumps are sized for no more than 10% voltage drop.

Batterie condition is relatively easy to check. Bad connections can be checked but there can be a lot to check, Fuse blocks and ground buss bars should be checked.
Finally, undersized conductors ( in effect more current drain than the circuits were designed to handle for small voltage drop) are usually difficult to fix since it can require new wiring both on the 12V side AND the common ground side.
 
dogdoc said:
house and start are separated with exception of acr's. as you may be aware the df250 lacks the aux charge wire commonly found elsewhere. prior to hanging the new engines i redid the battery compartment and added 2 blue seas acr's. i provided the shop with a wire from the ignition start interrupt but they said they could not make it work. boat is currently on a trailer so now is a good time to return to this problem. can you give some specifics on wiring. i have the wire connected to the si lugs but coiled up at the helm.
thanks
Click to expand...
Go on blue seas site and look at the diagram and instructions
 
seasick said:
The issue is voltage drop on the accessory buss. That can be related to many things, the more common being weak batteries (a load test can confirm), Confirm that you have the correct type and capacity batteries.
bad or corroded connections in the connections, fuse receptacles, battery switch and all common ground circuits.
Finally, your accesory laods may be greater than the wiring was sized for. Electronics should be connected by circuits that are rated for 3% or less voltage drop whereas other loads like pumps are sized for no more than 10% voltage drop.

Batterie condition is relatively easy to check. Bad connections can be checked but there can be a lot to check, Fuse blocks and ground buss bars should be checked.
Finally, undersized conductors ( in effect more current drain than the circuits were designed to handle for small voltage drop) are usually difficult to fix since it can require new wiring both on the 12V side AND the common ground side.
Click to expand...
batteries are are sized appropriate and good condition. wiring is new and good as well. devices are powered by house bank which other than the acr's charge circuit are fully independent.
 
SkunkBoat said:
Go on blue seas site and look at the diagram and instructions
Click to expand...
i did and all but one wiring diagram shows si wire going to start lug on key switch. mine are sealed units and as i said cutting harness may void warranty. one diagram did show the si wire going to the starting wire connection on the starter solenoid. seems that would suffice and a wire could be run thru the rigging tube.
 
dcpoweronboard.com

DC UPS: StartGuard - Newmar DC Power Onboard

The abrupt DC system voltage drop that accompanies engine starting can cause communication/navigation electronics to “dump” programmed memory. StartGuard solves this problem by providing supplemental voltage to sensitive electronics while the engine is cranked. It contains a sealed rechargeable...
dcpoweronboard.com

maybe look into something like this if other avenues don't rectify it. never used one. probably many other brands.
 
dogdoc said:
i did and all but one wiring diagram shows si wire going to start lug on key switch. mine are sealed units and as i said cutting harness may void warranty. one diagram did show the si wire going to the starting wire connection on the starter solenoid. seems that would suffice and a wire could be run thru the rigging tube.
Click to expand...
idk what the mechanicalal key/start is like. On my fly by wire, the KEY does not have a start position, just an ON position. There are start buttons for each motor.
Running to the start solenoid sounds like a good option.

Like seasick said, there are a lot of underlying causes to electronics blinking BUT...if the House Bank is isolated from the start batteries, starting will not cause a problem on the house.
You may have problems when running a pump, or keying VHF...etc.
So looking at all connections to Bat switches,ACRs,40A House breaker, terminals under helm, fuse panel/blade fuses, connections from terminals to fuse panel.....everything....would be a good thing to do. Look at wires for green corrosion. Make sure all of the battery/switch/ACR wires are the same 2 gauge. SI wire would be a smaller wire. House should be 6 gauge.

Put your eyeballs on evrything. Take things apart.

Also, make sure they separated the Suzuki gauge N2K power from the rest of your N2k network. Your gauges should come on with key. Your N2k network should get power from your fuse panel.
There should be a power isolator connector between the two Zuke gauge drops and the rest of the network.


I'm not looking at your setup so I can't give much more help than that.
 
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One thing not mentioned is that the new motors may draw more current than the old motors did when cranking. In that case, it is possible that the wiring is undersized. There are amp probe type of clip on meters that can measure current. Just knowing the current is not enough though, you need to know the end to end voltage drop and what the tolerance limits are for your MFD.
Using a decent digital voltmeter can help identify excessive voltage drop. The first logical step is to examine all cable ends and connection from the battery to the end point,the MFD. As I have mentioned, the grounds are as important as the feeds.
Do not rely on the voltage displays available on many plotters, or even engine displays. That are often not accurate.
One last point: It is possible that the 'new' wiring may be undersized for the new motors. Also when you say all the wiring is new, All the wiring including battery to switch cables and ground busses?
 
These ACRs are voltage sensing relays and I would imagine have diodes? which prevent current from passing from the house bank. To me that would mean a voltage spike causing the problem not voltage drop. I did wire a switch to the negative of the ACRs so they are disabled during charging when hooked up to shore power. When back in the water I may try and experiment to start engines with AP on and ACR switch off.
Of course my switch has an off-on-start position, it comes with the am radio
 
dogdoc said:
These ACRs are voltage sensing relays and I would imagine have diodes? which prevent current from passing from the house bank. To me that would mean a voltage spike causing the problem not voltage drop. I did wire a switch to the negative of the ACRs so they are disabled during charging when hooked up to shore power. When back in the water I may try and experiment to start engines with AP on and ACR switch off.
Of course my switch has an off-on-start position, it comes with the am radio
Click to expand...
It has electronics that control a RELAY that Combines (makes parallel) the batteries when there is a charging source(running motor). It isolates the batteries when there is no charging source(motor not running). There are thresholds of voltages that cause Lockout(prevents Combining). Without the SI Start Interupt, the current draw of the starter motor will adversly effect the House load.
the SI forces isolation of House Bat from Start bat when you turn the Key to Start.
You do not have SI connected. So it is not doing that.
 
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