Regulator melt down

Crater

Petty Officer 2nd Class
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Jun 21, 2009
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102
What would cause the regulator/rectifer to get hot and actually melt?
I know that it could be a dead short somewhere but where? And do they just go bad and short out themselves?
 

jimg984

Chief Petty Officer
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Jul 16, 2007
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Re: Regulator melt down

yes, but need to check out stator before replacing reg/rect
 

Crater

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Jun 21, 2009
Messages
102
Re: Regulator melt down

yes, but need to check out stator before replacing reg/rect

my manual says there is a low and high rpm test for the stator, this would require me to run the motor, will it run without the reg installed? Also the stator has already been updated to the red one, however is it still a possibility that the stator burnt it out?
 

jimg984

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Re: Regulator melt down

to test need to OHM with a meter the stator circuits out to see if one may open or grounded (burnt open or shorted to ground)
 

j_martin

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Sep 22, 2006
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7,474
Re: Regulator melt down

Merc regulators, especially the old clear potted ones, seem to melt down just for grins and giggles.

Ohm the stator, and throw a new CDI one in. Theoretically there's nothing that could go wrong with the stator that would hurt a regulator, and a dead short shouldn't hurt either one by design. (I said theoretically, didn't I)

A combination of high load and high temp under the cowl has a negative effect on component life fer sure.

hope it helps
John
 

Crater

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Re: Regulator melt down

I Ohm the stator .05 manual says between .06-1.1 is acceptable mines a little low but I think it could be just the contact between Ohm meter and yellow wire. BUT after inspection a little closer look I see the bullet connection of one of the yellow stator wires has also gotten hot, any reason for concern there or do you think it was because of the reg. BTY yes it was the clear potted OEM reg I think, part # matches orginal.
 

Crater

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Re: Regulator melt down

Also some opinons would be nice of what I did prior to this.
1) added Lowrance HDS-5 Depth finder (replacement for the missing Garmen)
2) Replaced blower (and ran all the time motor was running)
3) got all the lights (bow and stern) working
4) got the trolling motor running (seperated battery system though)
5) replaced the bildge pump

I wouldn't think that any of this would create too much draw on reg. but whats your thoughts
only thing that might draw a little more would be the depth finder I would think.
 

Crater

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Jun 21, 2009
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102
Re: Regulator melt down

Ok, looked into CDI reg/ret. Is it that good? $150.00:eek: compared to OEM for $70.00
 

Fl_Richard

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Jan 21, 2005
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1,428
Re: Regulator melt down

FYI most consumer grade volt/ohm meters have a really hard time measuring very low impedance loads. .05 MAY be OK
 

Crater

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Messages
102
Re: Regulator melt down

My ohm meter is a Sperry Mutimeter I don't know that much about it though I bought it to test 110v AC household current and read on net how to read the Ohm's

I ordered the CDI off the net $110.00 with shipping, local dealer wanted $166.00 Can you say MARKUP.

One thing that bothers me about my local dealer, he sells me parts at full list price, rite out of the book. I'm in sales also and relize that dealers get wholesale pricing. I would at least take the list price fanagle some numbers so it looks like I'm giving you a discount even if it does come back to full list price. Now he has lost all the profit just because I did some research and found I could buy it for less, NO ALOT less, I guess if you got the Merc market tied up in a city of 130K more friggen power to them. Well thats my flame for now.
 

j_martin

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Re: Regulator melt down

The bullet connectors are a weak point. I replace them with soldered and heat shrink insulated connections.

It makes it harder to replace parts, but one of the reasons for failure is removed, that is heat generated at a loose connection migrating down the wire and helping to fry the regulator.

My next 16 A to 40 amp conversion will move the regulators into the boat, where it is cooler. Connections to the regulators will be soldered ring terminals and a barrier strip.

hope it helps
John
 

Crater

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Messages
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Re: Regulator melt down

I guess this would be the time to relocate it if I'm going to then. Would there be any measureable voltage loss due to the longer wire lead though? Even using heavier gauge wire for the extension dosen't account for the stator and tach leads or the wires coming out of the reg itself.
 

Crater

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Jun 21, 2009
Messages
102
Re: Regulator melt down

The bullet connectors are a weak point. I replace them with soldered and heat shrink insulated connections.

It makes it harder to replace parts, but one of the reasons for failure is removed, that is heat generated at a loose connection migrating down the wire and helping to fry the regulator.

My next 16 A to 40 amp conversion will move the regulators into the boat, where it is cooler. Connections to the regulators will be soldered ring terminals and a barrier strip.

hope it helps
John

I was thinking about relocating CDI now but I know it body grounds to the motor block, how do your wire it up remotely. Also my wiring has only four wires :Red(+bat) 2-yellow(stator), Grey(Tach) I beileve CDI is coming with either 5 or 6 wires. I have read that one of the red wires from the CDI is not used and I hope the 6th wire is black(ground) so I can use it for the remote location.
Any ideas
 

j_martin

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Re: Regulator melt down

I was thinking about relocating CDI now but I know it body grounds to the motor block, how do your wire it up remotely. Also my wiring has only four wires :Red(+bat) 2-yellow(stator), Grey(Tach) I beileve CDI is coming with either 5 or 6 wires. I have read that one of the red wires from the CDI is not used and I hope the 6th wire is black(ground) so I can use it for the remote location.
Any ideas

Five and 6 wire regulators will handle up to 20 amps.

The two yellows go to the stator.
The 2 reds both go to battery. hook both up.
The grey wire goes to tach. On a 40 amp system, only one is hooked up.
The black wire goes to ground, or else the system is grounded through the case.

Remote mounting, just be sure you have a stiff ground return to the engine frame or Battery negative. I'd use 10 G wire. Any voltage developed across the ground wire corrupts the operation of the regulator circuit.

You can remote 5 wire units by bolting them to a metal plate. You should anyway for heat transfer to air. If the mounting plates, or heat sinks, are isolated, you can actually safely and effectively wire them into a 12/24 V charging circuit (dual reg 40 amp system)

Actually, if there's a proper place on the engine for a CDI regulator on a 16 amp system, it should be fine. I'd just solder the yellow and red wires.

hope it helps
John
 

Crater

Petty Officer 2nd Class
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Jun 21, 2009
Messages
102
Re: Regulator melt down

Ok, a little confused now.
Reg is a 5 wire from CDI
motor has 4 wires :Red, 2-yellows and grey
I wired it like so: yellows to yellows---Grey to Grey--- and larger of the two (from CDI) to the red Then as per the directions from CDI I taped off the smaller of the two red wire (from CDI)
What do you mean when you said hook both red wires up?

There is a nice spot for the Reg to mount to the motor and provides grounding also I sanded the paint off the mounting plate then used electrcial grease on mounting plate before mounting it.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Regulator melt down

Ok, a little confused now.
Reg is a 5 wire from CDI
motor has 4 wires :Red, 2-yellows and grey
I wired it like so: yellows to yellows---Grey to Grey--- and larger of the two (from CDI) to the red Then as per the directions from CDI I taped off the smaller of the two red wire (from CDI)
What do you mean when you said hook both red wires up?

There is a nice spot for the Reg to mount to the motor and provides grounding also I sanded the paint off the mounting plate then used electrcial grease on mounting plate before mounting it.

If CDI says do do it that way, then do it.
If it were a mercury regulator, you would connect both reds to the battery.

It would be my guess that CDI has some internal current limiting circuitry that would allow the same unit to be used in 16 and 20 amp systems with that circuitry, which would be system dependent.

That's the old burned out EE in me. Just do like they say.

Yer good to go.
John
 

Crater

Petty Officer 2nd Class
Joined
Jun 21, 2009
Messages
102
Re: Regulator melt down

Thanks for the info and help, hopefully I'll get to take her out this afternoon and see what happens. I'm really getting tired of the "take it out-bring it back home and work on it" slump I'm in.
I must be getting old, I used to love getting my hands greasy, there's (for me anyway) a great deal of satifaction when I can take something that's broke and fix it or better yet, improve it. :)
 
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