Johnson 1997 150 Ocean Runner Charging / Tacho problem

[Crashtackle]

Hi,

After reading some posts I am starting to think there is a connection between a charging problem and a tacho problem. I have hept my batteries fully charged. I have only owned the boat 6 moths and it has about 220 hours on it and the motor is well serviced and runs really well.

I have noticed that the tacho has been intermittent and work at times but on my last trip off shore the tacho did not work. I was using one battery and with the sounder,and radios on for 6 hours, the battery was flat when ready to come home. I switched to the spare battery and come home.

I voltmeter did not come up over 12 volts on the return home.What voltage should the charging system reach when working properly. I started the boat up at home and disconnected the batteries to see if the system would keep running on the charging system and, the motor still kept running with no battery connected so, something is working and maintaining voltage, but still no tacho.


As I live in the country and about 100 miles from the coast and a marine shop I have ordered a ampmeter to wire in to see if I have a charge. I am still waiting for the ampmeter at this stage. What amps and volts should the 150 Johnson charging system put out to be considered acceptable or what would be causing the charging / tacho problem.

My gut feel is the problems may be connected. I have checked all the fuses and okay. I want to get it working before I take the boat out again.

Thanks for reading this and I hope you have a solution for me.

Pete

 

[jonesg]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

Disconnecting a running engine from the battery usually blows some of the electronics, not sure exactly but I think rectifier is high on the list.
Powerpack could be vulnerable too, you can do $500 damage in 2 seconds.

Even loose battery terminals cause damage.
Better get yourself a factory service manual and have a good read.
www.outboardbooks.com

 

[Boblester40]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

Water cooled rectifier will most likely be the cause , be carefull there has been reports of them bursting into flames shortly after failing. I had to replace mine becuase the tacho stopped working.

 

[Crashtackle]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

Thanks for your reply. I have ordered an ampmeter to wire this in to have an idea what is going on. Like I say, we have no marine shop where I live and my ampmeter is still coming. I charged the batteries and started the motor. The battrery voltage was 12.3 after I cranked her and got her going and slowly brought the volatge up to 12.65 when running. Shut her down and repeated and got a similar result. It is sort of saying it is getting some charge.

I have to go to the city tomorrow, so I will pick up an ampmeter there and try that before I start buying retifier/regulator. Does anobody know what the voltage should be? I checked my car, and it sits on 14.2v with the engine running. I would think a boat would need to be similar.

CT

 

[Crashtackle]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

PS. Does the rectifer sit on top of the motor bolted down under the plastic cover. If so it looks like the water cooled type.

 

[Chris1956]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

I have a motor with the same Voltage Regulator. The service manual describes a test where you introduce load to lower battery voltage to the regulator to force the VR to charge. They also cite that the fylly charged battery should be at 14.5VDC. I do not have the variable load device, so if I were you I would look at the voltage at the battery to be near 14.

 

[Faztbullet]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

It sounds as the rectifier/regulator has crapped out. Disconnecting battery leads while running, loose connections and battery selector switching while running can all damage the rectifier on this model. I highly suggest you use a isolator if your going to run dual batterys on this engine. Below is diagram of how to wire in a isolater(guest or other brands) to charge both batterys. Move all your assy's to #2 battery so only engine is on #1 battery....

 

[Crashtackle]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

I do have an isolator/selector on the twin batteries. I started the motor and turned on all the accessories on the boat to drain some power. The volts at the battery were 12.3. 11.6 at the sounder and about the same on the dash. This was real with my voltmeter as I checked at the gauge with my hand held to cross check with the dash mounted dial.

I looked at the recifier and it does not look overheated in any way. I have gone over all connections and cleaned and checked for faults and all is good. I may have to oder a rectifier and hope that this is the problem. Very expensive if it is not the fault though. But, it has got to be right as it is a gut renching feelling when you are off shore 60 miles and the battery is flat.

Would the stator be a problem. I would have thought that all that stuff was pretty reliable.

 

[Faztbullet]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

Looks have nothing to due with rec/ret,unless diode has blown a hole in potting compound. Disconnect the yellow stator leads from rectifier and ohm across them to see if stator is open which I doubt. Reconnect and select 1 battery only, bring engine up to 2000 rpm, voltage at battery should then be right at 13 volts,if not replace rectifier.

 

[Crashtackle]

Re: Johnson 1997 150 Ocean Runner Charging / Tacho problem

Just a follow up to let anyone know who has a similar problem. The unit is now operating. Tacho and charging too. It seems a faulty connection where the rectifier plugs to the wiring harness is the problem. I pulled out the rectifier and it looked okay but a little bit of crusty plastic was in one of the connectors which I picked out. I found a rectifier to buy and decided to put it together and so I would not loose and bits. Decided to fire it up again when I assembled it back and, hey presto, I all works and tacho is away also and volts climbing in the dash mount and sounder voltmeter. Persistance and patience paid off this time, and the advice from this forum was a great help.

Thanks.