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Ignition problem

J

Jray

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Hello, so I have a two battery system on an 87 evinrude outboard. I have a battery switch with 1-2-both on it. I keep blowing gauges (fuel-tach). I did some testing when boat is running on switch 1 I have anywhere from 12.9 to 14v (motor charging battery) on switch 2 I have the same volt. On both i have the same volt. When I turn switch to off I have 30v i believe this is where the gauges blow. What would cause this higher voltage in off position.
 
Jray said:
Hello, so I have a two battery system on an 87 evinrude outboard. I have a battery switch with 1-2-both on it. I keep blowing gauges (fuel-tach). I did some testing when boat is running on switch 1 I have anywhere from 12.9 to 14v (motor charging battery) on switch 2 I have the same volt. On both i have the same volt. When I turn switch to off I have 30v i believe this is where the gauges blow. What would cause this higher voltage in off position.
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You don't give any details of the engine apart from its year of manufacture but I guess it has a non regulated rectifier ?


You do not say how your selector switch is wired ( many people regard these 1,2, both, off switches as an invention of the devil and best thrown in to the nearest garbage skip)


If you have the switch wired with the engine and the instruments connected to the common terminal and the batteries to terminals 1 and 2 so that it simply selects which battery, or both, you have in service DO NOT switch to OFF while the engine is running.

If you do there will be big spike in the volts which may well blow your instruments and the rectifier.

If you need to change from one battery to the other while the engine is running you must switch via the BOTH position
 
Evinrude vro 70
E70ELCUR
Sorry I am a newbie have never owned a boat before. I followed this diagram the boat did not have a switch or fuse panel. It had house speaker wire ran for a lot of the wire. So I bought wire and ran all new. There is another wire coming of of the start battery that goes to its own box with some relays and wires for tilt trim on bow and drivers toggles I did not change or touch that as it worked and seemed like adequate wires.

The gauges are wired of off three wire that come from omc shifter purple, black, grey.
Purple to positives (I) on gauges
Black to negatives on gauges
Grey to send on tachometer
 

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Update, so i talked with a friend who is an electrician. Apparently its called "ferroresonance". I guess there is two field terminals on the switch that need to be hooked up some how to cut stater off or send unused current to ground. He doesn't work on boat motors, just told me this over the phone. So I guess I will be doing more homework trying to figure this out unless someone knows how to explain to a newbie how to do this. Thanks in advance.
 
Sorry but you friend is incorrect as only applies to AC circuits..Check voltage on purple wire when cut off when you see this higher voltage.
 
Jray said:
Update, so i talked with a friend who is an electrician. Apparently its called "ferroresonance". I guess there is two field terminals on the switch that need to be hooked up some how to cut stater off or send unused current to ground. He doesn't work on boat motors, just told me this over the phone. So I guess I will be doing more homework trying to figure this out unless someone knows how to explain to a newbie how to do this. Thanks in advance.
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Tellyour friend thanks but no.if your boat is wired like diagram,turn asseoiry circut breaker off and recheck the voltage.
 
Personally, I would remove it, as Vic implied. If the second battery is just an emergency back-up, I would manually hook up when needed.
 
https://www.bluesea.com/resources/91

This is what he was talking about, except I don't have a alternator, I guess I have a stator.
The purple ignition wire is where I have voltage spike.
I was keeping house separated not as a backup I dont know if its true but I was told never to fully discharge my starting battery.
It seems pretty simple just to never turn switch off when engine is running I'm just worried if it accidentally happens or someone else does i will blow gauges and have to replace.
If I was to just get rid of switch how would I charge house battery?
 
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Jray said:
https://www.bluesea.com/resources/91

This is what he was talking about, except I don't have a alternator, I guess I have a stator.
The purple ignition wire is where I have voltage spike.
I was keeping house separated not as a backup I dont know if its true but I was told never to fully discharge my starting battery.
It seems pretty simple just to never turn switch off when engine is running I'm just worried if it accidentally happens or someone else does i will blow gauges and have to replace.
If I was to just get rid of switch how would I charge house battery?
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The stator is a part of your alternator,tell your friend no
The purple wire is not an ignition wire.
The motor is only going to maintane the battery or both you have selected on the switch.
Again,what is the voltage on the purple wire at gauge?
 
Rwbutler said:
The stator is a part of your alternator,tell your friend no
The purple wire is not an ignition wire.
The motor is only going to maintane the battery or both you have selected on the switch.
Again,what is the voltage on the purple wire at gauge?
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Ok purple wire sends 12v to gauge when key is turned and switch is on (1-2-or both)
When motor is running purple wire sends 12.9 to 14v to gauge on (1-2-or both)
If motor is running and switch turned to off purple wire spikes to 30v
When motor is not running and key is left on and switch is turned to off 0v
 
Simple. When you turn the switch to OFF, you are disconnecting the motor from any battery and the alternator is running on open circuit. That causes uncontrolled high voltage which blows accessories and the alternator rectifier. NEVER turn the switch off while engine is running.
 
Is it safe to have switch on both while engine is running to charge both batteries?

So there are no worries of over charging batteries?

There was never a fuse/breaker on trolling motor that is connected directly to house battery is one needed?

Thank you very much for your input.
 
Actually running the trolling motor on both position is drawing electricity from both batteries, meaning you are drawing down the starting battery, which is defeating the purpose of having a switch in the first place.
 
That motor only has a 9 amp stator so your not going to notice any battery replenishment unless you run WOT for several hours between use.
 
faztbullet said:
That motor only has a 9 amp stator so your not going to notice any battery replenishment unless you run WOT for several hours between use.
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Well that sucks for me (back to trickle charge I guess)

Thoughts pros vs cons any other options
O'Reilly told me not to trickle charge will ruin battery true/false
 
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