16+ Volts - Help!

[TralierTrash]

I've been scanning these forums for a while and have some questions. With no avail I've sought help from multiple sources, which all lead to the same answers. I've tested what I have been instructed to test. Replaced parts and still have an issue that has no resolution.

Motor is a 1976 Johnson 55hp. There are about 30 hours on the motor. Freshwater use. Stored dry, in a dehumidified garage. This s pushing a 14' Fiberglass closed bow, runabout.

The engine runs great, does not overheat, pushes the boat at about 33mph.

The question about the motor pertains to voltage. Both on the dashboard Voltmeter and confirmed at the battery with a multimeter, with all other electric disconnected from the battery other than the motor, the voltage is normal at idle, but spikes to nearly 17 volts at running speed. This is a cause for concern. I was alerted to the problem after two starter solenoids failed. The cause of the failure was traced back to high voltage. I've tested cables for resistance and unless I haven't tested properly cannot find a defective battery cable or bad ground. The battery is new and rated above the minimum stated in the owners manual. I made the assumption that the voltage regulator/rectifier was defective so replaced it as a precaution. I retraced wiring and cannot find a fault ground or cable that is creating higher than normal resistance. I do not want to damage other expensive parts.

Any thoughts or recommendations would be sincerely appreciated.

 

[Daviet]

Re: 16+ Volts - Help!

I don't think I understand,are you saying the solenoids were damaged by high voltage? Without the engine running the voltage at the solenoid should only have battery voltage, 11.5 to 12.5 volts. Do you have a factory manual for this engine? I think the charging system basically is made up of rectifier and stator. The faster the stator turns, the more output. I am sure someone with more knowledge will come along and help you out.

 

[Vic.S]

Re: 16+ Volts - Help!

You refer to the rectifier regulator. You should not get 17volts from a regulated rectifier but the parts diagrams appear to show just the round non- regulated type of rectifier!

The volts you get from these can rise quite high although the load imposed by the battery normally keeps it down.

Can you confirm the type of rectifier fitted.

Also what type and size of battery is fitted?

 

[Solittle]

Re: 16+ Volts - Help!

You refer to the rectifier regulator. You should not get 17volts from a regulated rectifier but the parts diagrams appear to show just the round non- regulated type of rectifier!

The volts you get from these can rise quite high although the load imposed by the battery normally keeps it down.

Can you confirm the type of rectifier fitted.

Also what type and size of battery is fitted?

First check the simular posts at the bottom of the thread. I would als double check the cables. I have seen cables that look fine, test fine but the insides are mostly that green soup nasty stuff.

 

[F_R]

Re: 16+ Volts - Help!

The 1976 55hp came with the unregulated alternator. A regulated 12amp system was an option.

Having said that, it is absolutely normal for the unregulated system to go up to 16 or even 17 volts. Everybody freaks out when they see that, but it is really no concern. If it were, there would be many thousnds of boats out there in trouble. Including mine.

Oh, and I have never had a solenoid go bad. Never. But now I am beginning to wonder if there might be some poor quality solenoids out there on the market. Another thread dealt with the same (solenoid) problem.

 

[TralierTrash]

Re: 16+ Volts - Help!

Thanks for all of the help.

To answer the battery question. It is a new battery, size e24MS-N with 625 amps of cranking power.

I did test the cables and found no resistance issues.

I purchased the rectifier from iboats and it was listed as a regulator/rectifier, but I am only speaking from that knowledge. Where it attaches to the motor it is a D shape at the base. 153-3408 is the CDI Part #.

The solenoid went out twice on two separate trips. It could be that a loose battery cable was the culprit on either or both solenoids failing, but it was the cause of those failing that prompted me to look.

Additionally, the high voltage, I'm assuming will likely cause a problem to other electronics on the boat. I am currently using a power inverter to power a radio, which cuts out when the boat is running because the voltage gets too high.

Some here have said that the voltage is nothing to be concerned about, but it seems that the voltage should be lower.

 

[ezeke]

Re: 16+ Volts - Help!

What you bought is an unregulated rectifier. It can be regulated; contact CDI Electronics for the regulator specifications if you are concerned: http://cdielectronics.com/TechService/tabid/65/language/en-US/Default.aspx

 

[TralierTrash]

Re: 16+ Volts - Help!

Thank you ezeke.

I will check into that.

If the situation isn't abnormal, I'm not going to worry. The question then would be more general, would 17 volts going other places than the motor cause a problem?

 

[F_R]

Re: 16+ Volts - Help!

Thank you ezeke.

I will check into that.

If the situation isn't abnormal, I'm not going to worry. The question then would be more general, would 17 volts going other places than the motor cause a problem?

I would hazard to say that since it is so common, marine electronics manufacturers are aware of it and design their instruments with some sort of input voltage regulation. If they don't, they should.

Will it shorten the life of the battery? Well in theory, yes. Is it really a big deal? Wanna know how badly my battery has been misused and abused and is still ticking?

Will it shorten the life of light bulbs? Well they generally are rated for up to 16 volts anyway, but it does put them at their maximum design range. Besides if you have all the running lights on, it might not go that high anyway.

 

[brianvolt7]

Re: 16+ Volts - Help!

Wouldn?t worry about 17volts to lights and peripheral devices on your boat. The manufactures of this equipment take this into consideration, start worrying if it drops below lets say 10 or 11 volts. Low volts or brown out to equipment is much worse on it than 17 volts.

 

[TralierTrash]

Re: 16+ Volts - Help!

Thanks for everyone's help and suggestions. The remaining question then is regarding my Power Inverter, which has a safety cutoff at 16 Volts. This can only be used with the engine at idle or off.

Any thoughts on how I could reduce the voltage or keep it from rising above 16 volts?

 

[tx1961whaler]

Re: 16+ Volts - Help!

Thanks for everyone's help and suggestions. The remaining question then is regarding my Power Inverter, which has a safety cutoff at 16 Volts. This can only be used with the engine at idle or off.

Any thoughts on how I could reduce the voltage or keep it from rising above 16 volts?

There is an Evinrude voltage regulator available for your motor, but it is $187

Product Details:

Part Number: 0581580
Description: VOLTAGE REG AY
Pack Qty: 1
Dimensions: 4.51 x 2.00 x 2.00 (in)
Weight: 0.57 lbs
Equivalent Parts: N/A

 

[Faztbullet]

Re: 16+ Volts - Help!

You can try to find a regulator off a early model Mercury Xr2 or Magnum and use it, part #88825A7. Most shops remove them as fishermen use to many assy's and need the extra charging.

 

[newfiez]

Re: 16+ Volts - Help!

I've been running my set-up on my '79 55 for 2 years with no issues on the equiptment. It runs the same as yours, and if the volt meter always goes to 16 volts at driving or WOT, then you have a fully charged battery. If you have a low battery, or a good load on the system...you should see ~14.5 volts.