AQ 125 alternator smoked and now nothing

[freeboats]

I was running across the lake today at about 3800 RP Ms and stopped at party cove to swim. first the engine would not shut off so I jiggled the key and she shut off, then I noticed gauges where bouncing around like they were getting small power surges (the key was out of the ignition) and I smelled some burning plastic. I pulled off the engine cover and the alternator was smoking

I grabbed a wrench and disconnected the battery. but the alternator contiued to smoke, I splashed a little water to put it out.(Yes I have an extinguisher on board but did not want to make a mess)
hooked the battery back up and she started fine so I headed back to the dock(sans swim)
I was limping along ok and tried to give it a little more throttle she died
Now I have nothing when I turn the key no gauges not even a click from the starter.
the Bilge pump and blower still work.

I did reset the breaker

so I probebly need to rebuild or replace the alternator Right?

also any ideas on what else I have damaged, and how I might begin trouble shooting

 

[Don S]

Re: AQ 125 alternator smoked and now nothing

Once you let the smoke out of something, it's dead and needs replaced.

I think you need to take a hard look at your ignition switch and wiring.

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

the ignition switch looks fine, should I just replace anyway?
I do remember noticing the ground wire to the Block from the alternator was hot while running on muffs in the yard about two months ago, but that is not where the fire seems to have started

 

[Daviet]

Re: AQ 125 alternator smoked and now nothing

I think the cluster is fed voltage through the ign switch. I would disconnect alt and wiggle ign switch and see if I could make guages move as before. You will probably have to replace alt or at least have yours rebuilt. What type of engine do you have?

 

[bruceb58]

Re: AQ 125 alternator smoked and now nothing

Never heard of a ground from an alternator to the block. Typically, the alternator is grounded through its bracket.

Also, when you turn the key on you are sending voltage to the alternator to energize the field and when you turn the key off, the field is disconnected. Apparently, your alternator failed and the field voltage was still applied somehow. This was probably caused internal to the alternator which explains why the engine kept running. In the process, I am sure the fuse that drives the ignition blew so you need to check that as well as replacing the alternator.

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

the engine is a volvo penta aq 125a.

I dont think I have ever seen a ground on an Alt. either, that struck me as unusual. is this comon in boats.

If I can walk away with a blown fuse and a new alternator, I will consiter myself lucky

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

Today I got down to the lake to look at the damage on the boat,

I think I have found a problem with the wire that supplies power to the ignition switch,

if I run a jumper from the battery to the "B" post on the ignition switch, the motor turns over well. so my first question is, can I hard wire the switch to the battery to run the boat?

Also the battery is reading 32 volts , is there a way to discharge the battery(like run the boat with no alt for and hour or two) or should I not worry about it?

and finally, why would an alternator over charge to to the point of self destruction???

I could not find any fuses blown anywhere( 40amp breaker and fuse on the motor above the starter and the fuse panel behind the dash) is there another place to look)

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

bump

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

Nope, just one battery, and it reads 32 volts on my cheap meter but the meter reads 12 volts on my car.

 

[freeboats]

Re: AQ 125 alternator smoked and now nothing

I tried disconnecting the battery but I am still reading over 30 volts.

I started the boat tonight using a jumper from the battery, (I had to move to another dock, the weed guy is coming tomorrow) ran for about 5-7 minuets and sounded better than ever.

the alternator was disconnected and I had loosened the belt a little.

the ignition switch does not seem to be powered from the fuse panel. it should be right???
there must be a fuse in that wire someplace that blew.

Could a bad ground on the alternator be the root cause of this issue??

please help!!!!!