1986 Johnson 60 voltage overcharging problem

[boatingman_2001]

Hi,<br /><br />I’m trying to help my brother solve a voltage overcharging problem with his 1986 Johnson 60 HP, 3 cylinder, Model No. J60ELCDS, Serial No. J7122470. Until recently, after starting the boat the dashboard voltmeter would read around 12.5 - 13 volts. Now it begins normally but climbs quickly and doesn’t stop until it reads about 18 volts. Turning on the accessories only drops it a few volts into the 16.5 - 17 volt range. The battery is in great condition, we’ve tested the rectifier with a DVM and it appears to be ok. We measured the resistance on the stator leads to be about .6 - .7 ohms but we don’t know of it’s a 6, 9 or 15 amp alternator and couldn’t verify the measurement with the table in the Clymers manual that we have. Around the same time the overcharging problem appeared, the tachometer began to flake out and bounce all around the place. I’ve learned, perhaps too late, that we should never disconnect the battery when the motor is running but we did because we were in the middle of the lake and worried that we would cook the battery. As it turned out we toasted the fish-finder and the newly installed CD player. Even thought the rectifier appears to measure ok could we have damaged it? Possibly the stator or the power pack? What should we be looking for? Please help shed some light on this issue, thanks. <br /><br />Kevin

 

[moderator1]

Re: 1986 Johnson 60 voltage overcharging problem

Moving to Johnso/Evinrude Troubles/Repair

 

[rickdb1boat]

Re: 1986 Johnson 60 voltage overcharging problem

You can almost bet on the rectifier being shot after disconnecting the battery while the engine was running. Only takes a second. Even though it checked out right with the meter, it is still probably bad...

 

[boatingman_2001]

Re: 1986 Johnson 60 voltage overcharging problem

Thanks for the help and confirmation,<br />‘rickdb1boat’. From what I learned through previous threads about the same issue I suspected that we fried the rectifier. We're picking up a new one today and will continue troubleshooting ASAP. Only problem is...we leave on Thursday for our five day annual fishing trip and we don't have much time to get the boat fixed. Our plan, if the rectifier doesn’t solve the problem is to move the neg. and pos. feeds (which go to the dashboard fuse panel to power all of the accessories) from the starting battery and connect them to a backup battery (we have two deep cycle trolling batteries) and protect the accessories from the circuit that’s overcharging. If that plan is ok, we’ll be happy to recharge those batteries after each day of fishing. My new question is...If after installing the new rectifier we continue to have overcharging problems (BTW, I measured the the stator to be putting out 16.8 VAC with a Fluke DVM but I don't trust the reading) will it be safe to operate the boat with the dash voltmeter reading 17 - 18 volts DC without causing additional damage? I read in another thread that it's permissable to disconnect the stator and run the boat...is this so? Thanks again for everyone’s help...this forum has really provided us with a wealth of information.

 

[boatingman_2001]

Re: 1986 Johnson 60 voltage overcharging problem

Well, we're in trouble now! Changing the rectifier didn't solve the overcharging problem. It's probably too late now to get my hands on a new stator before leaving for our annual fishing trip. Any thoughts from anybody what else may be causing the overcharging and whether or not we'll do any additional damage by disconnecting the stator at the terminal block and running the boat without the alternator connected.

 

[Hooty]

Re: 1986 Johnson 60 voltage overcharging problem

That engine, like a lot of others doesn't have a voltage regulator. If the Fluke sez 16.8 and the dash v/m sez 18, I'd believe the Fluke. I'd hook everything back up like it was (except maybe the dash mounted volt meter) and not sweat it. Go slay tha fish.<br /><br />c/6<br />Hooty

 

[boatingman_2001]

Re: 1986 Johnson 60 voltage overcharging problem

Update!!! While my brother was doing process of elimination with the batteries he discovered that the starting battery and the one trolling battery that swapped into service were causing the voltage to climb up to 17-18V as read on the dashboard gauge. But the battery that was never put into service when the problem developed allowed the system to run at about 14-16 volts. He then remembered that the shop that did the shrink-wrapping at the end of last season left the starting battery in boat over the winter. He went out and bought a new starting battery and it did the trick, the new battery runs at around 14V. We still get up into the 15-17V range when running at higher RPM’s but just flick on the running lights to help drain a volt or two from the system and now know that this range is perfectly normal for this unregulated charging system. We never would have gotten to the bottom of the problem without all of the posts that we read through while tying to diagnose this problem Thank you very much to all of you for helping us solve the problem. We just returned from the fishing trip - the boat ran great and the salmon tasted fantastic! Thanks again, Kevin