Converter box buzzing and getting hot?

[CGraziano]

I just replaced the converter box on a 150 HP force (year 1992, model 1508X92C). When I re-connected the battery, I heard a faint buzzing sound. It was coming from the converter box and it felt like it was getting hot. I quickly disconnected the battery to avoid frying another converter box (they ain't cheap!!). I'm thinking I have another problem somewhere. It felt like the red wire that goes into the converter was the one getting hot, I traced the wire back to my solenoid. Is it possibly on the wrong side of the solenoid?

Thanks,
Carmine

 

[roscoe]

Re: Converter box buzzing and getting hot?

Hi, looks like you have it connected properly.
The red wire going to the converter box connects to the battery side on the solenoid.

Sorry I can't offer any additional insight.

 

[jason32038]

Re: Converter box buzzing and getting hot?

I see 3 wires on the power side and no ground on the solenoid. One big cable goes to the battery and the other big cable goes to the converter but what is the purpose of the small orangish looking wire and where does it go? Sorry im color blind.

 

[roscoe]

Re: Converter box buzzing and getting hot?

Yellow/red goes to the neutral safety switch.

Cable on right goes to starter.

Stud on the left connects the battery cable +, the fused power lead, the converter box, and the dc+ off the rectifier.

Yes it does look like there is no ground wire attached.

 

[fucawi]

Re: Converter box buzzing and getting hot?

Must be some sort of american terminology but what is a converter box ?Whats it converting ?

 

[CGraziano]

Re: Converter box buzzing and getting hot?

Hi Guys,

Thanks for all of your input. You were right, there was a ground wire at the bottom of the solenoid that was not attached. I connected it to the stud next to the yellow/red wire and re-connected the battery, but it made no difference. As soon as I heard the buzz I disconnected the battery.

I called the boat shop who looked at the motor originally to see if they could give me any more insight (they were the ones who told me the converter was bad). The gentleman who worked on it told me he was sorry, but could not offer me any more advice. He wasn't very familiar with this type of motor and did not want to take it back in for another look. So, I'm going to hit the yellow pages today to see if I can find someone who can work on the Force outboard. A friend of mine recommended a shop not too far from me, so I'm going to give them a call as well.

Thanks again,
Carmine

 

[jason32038]

Re: Converter box buzzing and getting hot?

Check the violet/white wire. It's the only one that isnt insulated at the connector and it also looks like it's touching the converter box. Im not sure if what it's touching is metal or plastic but maybe it's shorting out?

 

[roscoe]

Re: Converter box buzzing and getting hot?

Must be some sort of american terminology but what is a converter box ?Whats it converting ?

Its a rare and quirky ignition for a modern era engine. Battery driven, not alternator driven.

A little info on this ignition system.

The ignition on this motor is a battery driven capacitor discharge ignition.
THe converter box allows battery current to charge the capacitors.

The signal from the trigger flips a switch inside the converter box, this allows the converter to to convert 12v dc battery voltage to ac.
The ac voltage is amplified up, to 280v, (dc voltage can not be transformed)
The amplified ac voltage is converted back to dc, ( because ac cannot be stored) and this is used to charge the capacitors in the switchbox.

There iss a second signal from the trigger that trips a second switch in the converter box, which in turn signals the switchbox to fire.

 

[fucawi]

Re: Converter box buzzing and getting hot?

Yes rosco and thanks as soon as you said it was the generator for the CDI ignition I knew exactly what it was ..I even built one in the mid 70s..
Now haveing said that often these things do Buzz as they run at 400Hz which is in the audio range ..BUT if the output is shorted it may be loud ..they are designed to run or rather not stop when the capacitor is discharged ...so buzzing and hot = short on output ...??

 

[CGraziano]

Re: Converter box buzzing and getting hot?

Wow, this is really good information, thanks!

Fucawi, you hit it on the head. The issue I was having is that there was power into the converter box but no power coming out. I don't have a voltmeter right now to see what is coming out of the box now, plus when I heard the buzz i disconnected the battery to avoid frying another box. So, should I be looking at the blue and black wires coming out of the converter?

 

[fucawi]

Re: Converter box buzzing and getting hot?

you should BUT REMEMBER THIS IS A LETHAL AS 240V MAINS SUPPLY IF NOT MORE SO
I think you should be testing what its connected to it see if its short circuit....those SCR s in the triggering unit could be bugggered .....and are what buggered the original unit ....


study this circuit it will give you an idea of what is inside it
http://www.siliconchip.com.au/cms/A_110499/article.html

The coil on the left is the equivalent of your converter box ....you can see if the SCR is short circuit then it shorts your convereter box .....

 

[jason32038]

Re: Converter box buzzing and getting hot?

CG how do you know you have power going in but not going out without a multimeter? Have you tried rotating the flywheel a bit and then reconnecting the battery? Does it buzz with the ignition on and or off? Make sure the switch is off. Remove flywheel,stator and trigger and make sure there are no pieces of magnet on them.

 

[jason32038]

Re: Converter box buzzing and getting hot?

Also have you tried switching the ground and the other wire on the solenoid posts to see if that helps? Not sure if it will but its worth a try at this point. What's the worst it can do? Nothing?..Another question..was the other converter box buzzing before you changed it?

 

[fucawi]

Re: Converter box buzzing and getting hot?

dont go swopping wires as suggested ...you know now what the problem is ..check the output from the converter with its output disconnected ...should not buzz loud or get hot ....dont electrocute yourself.

 

[CGraziano]

Re: Converter box buzzing and getting hot?

Jason,

I had a friend come over who has a tester, that is how I determined there was no power coming out of the converter. I brought the motor to a local boat shop and they confirmed it. The boat shop did advise me that there could be other issues besides the converter box. Now that I have replaced the box, I don't have a tester handy to see what it is putting out now. I'll call my friend and see if he can bring it back over to the house. I got the buzzing sound as soon as I re-connected the battery, it almost sounded like a "wheeze" at first. The key was not even in the ignition.

Thanks,
Carmine

 

[fucawi]

Re: Converter box buzzing and getting hot?

Well it should be powered like any igniton through the ignition switch ..it should not fire up until you have the key in the run position ..the rising Wheeze sound is normal

 

[CGraziano]

Re: Converter box buzzing and getting hot?

I was able to get my hands on a volt tester for the weekend, so I did some testing on the new converter box. Here is what I got so far:

I disconnected the red wire from the converter box and hooked the battery up - no buzzing.

When the battery is connected:
Red Wire - 11.4V
Violet - 0
Black - 0
Blue - 4.15V

I disconnected the Blue wire and tested the actual terminal and got 0. Could power be flowing from the switchbox into the converter??

Previously, I was getting 12V so I think my battery could be losing some charge. I tested the battery and it is putting out a little under 12V (11.4 to be exact) . I have it hooked up to a charger for a few hours, I'll see if that makes any difference.

 

[fucawi]

Re: Converter box buzzing and getting hot?

well the battery needs a good charge 2 hrs not enough 24 ..a standing battery should be 12.5 + if its any good ....now to be silly are you shure its the converter thats buzzing ? did you put a finger on it and feel the vibration ? and yes the converter feeds the switch box with 2-300v and the switch box output is only to the coils ....

 

[CGraziano]

Re: Converter box buzzing and getting hot?

I let the battery charge overnight, and my charger is showing the green light so it should have a full charge. I'm in a hurry to get to work so I can't mess with it right now, but I'll check it out when I get home from work.

Thanks,
Carmine