1999 Mercury XR 6 Outboard

[mgoff]

Was going to power tune my outboard, turned on the battery switch and the lower CDI voltage regulator/rectifier started smoking. Anyone know what could cause this. The ignition switch was not turned on yet and the key was in my pocket.

 

[GA_Boater]

Have you done any battery or electrical work and might have a reversed connection.

 

[Dukedog]

reg went south.. change both and do away with tha bullet plugs.. solder and tape joints.... jan.. any/all "red" wires have 12v at ALL times when battery is connected.....

 

[mgoff]

reg went south.. change both and do away with tha bullet plugs.. solder and tape joints.... jan.. any/all "red" wires have 12v at ALL times when battery is connected.....

So the red wires from the stator always have 12V present when the battery switch is turned on?

 

[mgoff]

Have you done any battery or electrical work and might have a reversed connection.

I installed a new stator, trigger, both regulators, and 2 new switch boxes. All CDI parts. CDI tech support told me they never heard of one of their regulators burning up when turning on the battery switch but that a reverse polarity could cause that. Triple checked all wiring connections for the ignition system and they are correct. Could the battery or battery switch be causing that?

 

[sam am I]

So the red wires from the stator always have 12V present when the battery switch is turned on?

You mean regulator? Yellow wires go from the stator to the input of the rec/reg, red wires go from the output of rec/reg to the battery side of the starter solenoid.

You should NEVER have DC (12V) on the stator's yellow wires.

So yes, without the motor running and the battery switched "ON", both red REGULATOR wires now should have 12V on them........They run to and bolt directly to the battery side of the starter solenoid.

I've personally seen/read over the years of several regulators (maybe labeled "CDI" not sure in every instance but, Merc/CDI both get theirs from China just like I do although I use Amazon) red output wire short internally to the rec/reg to ground and fry the wire and/or loom the red wires ran in.........

Insert a 30A fuse in the 20A feed line and a 1A fuse in the sense line when you remove those bullet connectors like Duke suggested.

If you have one bad out of the box or in time where either of those red wires short to ground inside those rec/reg's, it sure as s**t can smoke!! BIG TIME...That's why Merc started fusing them on stock engine at some point.

 

[GA_Boater]

Did you disconnect the battery while doing work. Are the battery leads reversed?

 

[Dukedog]

So the red wires from the stator always have 12V present when the battery switch is turned on?

All red wires will have voltage to 'em if battery is connected unless someone has changed/modified wiring somewhere down tha line...………...

 

[mgoff]

So the red wires from the stator always have 12V present when the battery switch is turned on?

Correction, I see on the diagram that the red wires from the regulators connect to the positive terminal on the solenoid so they have 12v when the battery switch is on. The red and red/white wires from the stator connect to the switch boxes so I'm guessing they would only have 12v present when the ignition switch is turned on?

 

[mgoff]

Did you disconnect the battery while doing work. Are the battery leads reversed?

Any time I do electrical work on it I remove the negative cables from the battery with the battery switch turned off and the spark plug wires grounded to the powerhead.

 

[mgoff]

You mean regulator? Yellow wires go from the stator to the input of the rec/reg, red wires go from the output of rec/reg to the battery side of the starter solenoid.

You should NEVER have DC (12V) on the stator's yellow wires.

So yes, without the motor running and the battery switched "ON", both red REGULATOR wires now should have 12V on them........They run to and bolt directly to the battery side of the starter solenoid.

I've personally seen/read over the years of several regulators (maybe labeled "CDI" not sure in every instance but, Merc/CDI both get theirs from China just like I do although I use Amazon) red output wire short internally to the rec/reg to ground and fry the wire and/or loom the red wires ran in.........

Insert a 30A fuse in the 20A feed line and a 1A fuse in the sense line when you remove those bullet connectors like Duke suggested.

If you have one bad out of the box or in time where either of those red wires short to ground inside those rec/reg's, it sure as s**t can smoke!! BIG TIME...That's why Merc started fusing them on stock engine at some point.

Thanks for the great info. Can you tell me where to order the in line fuses that will fit right for this?

 

[mgoff]

reg went south.. change both and do away with tha bullet plugs.. solder and tape joints.... jan.. any/all "red" wires have 12v at ALL times when battery is connected.....

Thanks Dukedog, great info. I think I'll also install inline fuses that sam am I suggested.

 

[Dukedog]

"solid red" only..

tha reg "bullet connectors" build heat and are tha usual reason for reg failure... a soldered joint with heat shrink will pretty much eliminate that point...

 

[mgoff]

Thanks Dukedog, I noticed one of the red wire bullet connectors on the top regulator is discolored due to overheat. I'm going to order 2 new regs and cut the bullet connectors off and solder the joints with heat shrink tubing, Thanks for your great advise!!

 

[mgoff]

Need to order 2 new voltage regulators. I put 2 brand new CDI regulators in about 3 months ago and the lower one burned up when I turned on the battery switch. The upper reg. is showing heat discoloring on the bullet connector. Are the Sierra, or Mallory brands better than the CDI?

 

[mgoff]

"solid red" only..

tha reg "bullet connectors" build heat and are tha usual reason for reg failure... a soldered joint with heat shrink will pretty much eliminate that point...

Should I also get rid of the bullet connectors on the yellow stator wires to the regs and solder and heat shrink them?

 

[mgoff]

I ordered 2 new Sierra voltage regulators and I'm going to cut off the bullet connectors and solder and heat shrink them when I install them. I'm going to install a 30 amp use in the red feed line and a 1 amp fuse in the thinner red wire sensing line. Are these the only wires that need to be soldered or should I solder the yellow wires that connect to the yellow stator wires also?

 

[mgoff]

99 Mercury 150 voltage regulators wiring

I need to get rid of the regulators bullet connectors and solder and heat shrink the connections. I Also want to add in ATC in- line fuses, 30 amp feed wire and 1 amp sensing wire. I saw in the forums that Mercury changed to fused, soldered wires on newer models after recognizing the bullet connectors were heating up and burning up voltage regulators. Would it be better to install a small fuse block for each regulator and mount them on outside of the plate or just go with the in line fuses. If anyone has done this, please advise. Pictures would be helpful. Should I do only the red wires from the solenoid or should I also solder and heat shrink the yellow regulator wires coming from the stator?

 

[Dukedog]

Should I also get rid of the bullet connectors on the yellow stator wires to the regs and solder and heat shrink them?

yes, do all goin' to tha regs…
don't know where ya got it that merc did away with bullet connectors and added fuses but it ain't so with that type chargin' system...

 

[mgoff]

Thanks Dukedog! I copied and pasted sam am i's reply here. Should I install those fuses in the red rec/regs wires? Insert a 30A fuse in the 20A feed line and a 1A fuse in the sense line when you remove those bullet connectors like Duke suggested.

If you have one bad out of the box or in time where either of those red wires short to ground inside those rec/reg's, it sure as s**t can smoke!! BIG TIME...That's why Merc started fusing them on stock engine at some point.

Last edited by sam am I; February 15th, 2020, 11:35 AM.

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