Wiring near disaster

[Analgesic]

So, still shaking after feeling like I almost set the boat on fire today.  Briefly, I have a 1988 M25 XP, on the hard south of Boston.  Last Fall my alternator crashed, took it to local highly reputable battery guy who rebuilt it only to find that my Balmar Max Charge regulator was also dead.  The same guy sold me a Transpro regulator for much less $ than a new Balmar, said it would be fine since I sail mostly, use engine sparingly.  I decided to replace the terminal strip by my engine since it was looking very tired (prior owner did the wiring harness upgrade).  I then removed any corrosion and reattached every wire back at the Seaward panel in the cockpit and replaced a dead bulb on the engine temp gauge.  Thinking I would be just testing the light bulb, I turned the ignition key one click (not the extra to fire the glow plugs).  I heard the beeping alarm test and clicking of the fuel pump as usual. I then left the cockpit to inspect everything and saw smoke pouring out of the engine area.  The Brown wire (14 ga, see picture) going to the new regulator was smoking, melting and burning the wire cover.  I hope the attached picture adequately shows both ends of the short harness connecting the alternator to the regulator  mounted under the head sink .  Anyway, I think I'm pretty meticulous about hooking up everything.  However, clearly something disastrous is going on.  The brown wire where it goes through the 4-wire plastic unit to plug into the regulator has completely melted inside.  One answer is to wave the white flag and call somebody who knows what they're doing to fix this but I like to know what's going on and consider myself reasonably competent.  That being said, I don't want to set Analgesic and the rest of the boat yard on fire.  Thanks for any advice. 
Brian McPhillips

[KWKloeber]

Brian,

I'm not familiar with the regulator/harness -- what did you have the other end of the brown wire connected to?
Am I correct that it operated ok before replacing the terminal strip?   Or was this the 1st time you fired up since the alternator rebuild/new regulator?

The terminal strip?  is this the "euro strip" that comes with the harness kit, or a different strip?  Picture?

THIS IS EXACTLY what I have been saying for many years (a couple years on here).  The harness upgrade is CRAP because the end result is non-ABYC compliant, and is a fire hazard because there is no overcurrent protection on the harness, which is 100% LIVE whenever the battery selector switch puts power to the "B" post of the solenoid.  If the upgrade was compliant, the fuse or breaker would have blown --- indicating an issue (before the near disaster.) 

THANK YOU for  the practical demonstration of what I have BEEN YELLING!!!! Just too bad it had to happen -- but good that it ended the way it did.

Ken

[Stu Jackson]

Brain,

Sorry to hear this happened to you.

Thanks for posting that photo.  One thing I see that is missing from it is what the PURPOSE is of each of those wires.

When I did something like what you're doing, I drew a wiring diagram BEFORE I connected anything.  Like this (from the Electrical Systems 101 topic):

Alternator Regulator Wiring Diagrams - all three http://c34.org/bbs/index.php/topic,4548.0.html

This showed me not only the color of the wires, but what service they performed.  Your writing on the paper in your photo seems only to try to remember what color went where, not what each of the wires is designed to do.  I developed the diagram in that link along with the wiring diagrams of the panel from the links in the tech wiki Electrical and Engine sections.

It's late at night here now, so I'll get back to this in the morning.   But I suggest you do this so YOU understand completely just what color wire does what in each of your connections.

[mainesail]

So, still shaking after feeling like I almost set the boat on fire today.  Briefly, I have a 1988 M25 XP, on the hard south of Boston.  Last Fall my alternator crashed, took it to local highly reputable battery guy who rebuilt it only to find that my Balmar Max Charge regulator was also dead.  The same guy sold me a Transpro regulator for much less $ than a new Balmar, said it would be fine since I sail mostly, use engine sparingly.  I decided to replace the terminal strip by my engine since it was looking very tired (prior owner did the wiring harness upgrade).  I then removed any corrosion and reattached every wire back at the Seaward panel in the cockpit and replaced a dead bulb on the engine temp gauge.  Thinking I would be just testing the light bulb, I turned the ignition key one click (not the extra to fire the glow plugs).  I heard the beeping alarm test and clicking of the fuel pump as usual. I then left the cockpit to inspect everything and saw smoke pouring out of the engine area.  The Brown wire (14 ga, see picture) going to the new regulator was smoking, melting and burning the wire cover.  I hope the attached picture adequately shows both ends of the short harness connecting the alternator to the regulator  mounted under the head sink .  Anyway, I think I'm pretty meticulous about hooking up everything.  However, clearly something disastrous is going on.  The brown wire where it goes through the 4-wire plastic unit to plug into the regulator has completely melted inside.  One answer is to wave the white flag and call somebody who knows what they're doing to fix this but I like to know what's going on and consider myself reasonably competent.  That being said, I don't want to set Analgesic and the rest of the boat yard on fire.  Thanks for any advice. 
Brian McPhillips

Brian,

That is not a Balmar regulator, the Balmar version has an extra v-sense terminal, thus the wiring terminals are NOT the same. You connected the brown wire "switched 12V+" to the alternator regulators stator tap and the black wire (ground) to the ignition or lamp terminal. You need to get the correct wiring diagram for the Transpo. I suspect that is the V-1200 and they are normally from L-R: Field, Stator in (stator out is the terminal next to it but not in line), B+ and Ignition/Lamp the B- is over by the green light...... 

As Ken said you MUST be using over-current protection on every circuit on the vessel, this is the WHY! The previous installer did you zero favors and did a horribly unacceptable job installing the previous regulator...

[Analgesic]

Thanks.  I cannot find a wiring diagram for the Transpo regulator on line but the side of the unit has a sticker identifying the terminals in order as IASF corresponding to the Black, red, brown and Navy wires in the plug connector in my photo.  The terminal just next to these 4 is labeled Stator Output-this is where I attached my free black wire and, along with the brown "S" wire, also looks cooked.  Is it as simple as the free black should have gone to the "B-" post adjacent to the green light? 

[Stu Jackson]

Brian, perhaps, but I refuse to say yes or no, and so should everyone else.  I strongly suggest you reread my post and Maine Sail's.  BOTH of us suggested that you find the NAMES of the connections on that regulator and do what I suggested as far as the wiring.  I would also suggest you call the bloke who gave you that regulator and tell him about your issues and have him help you find the information you require.

[KWKloeber]

Thanks.  I cannot find a wiring diagram for the Transpo regulator on line but the side of the unit has a sticker identifying the terminals in order as IASF corresponding to the Black, red, brown and Navy wires in the plug connector in my photo.  The terminal just next to these 4 is labeled Stator Output-this is where I attached my free black wire and, along with the brown "S" wire, also looks cooked.  Is it as simple as the free black should have gone to the "B-" post adjacent to the green light?

Not quite that simple  The plug is wired differently.

As Stu said before plugging things together you need to understand what the function of EACH wire/terminal is -- colors can be interchanged, duplicated to different terminals (and color standards are not always "standard") and plugs can be wired "reverse" or just in a different sequence between mfgrs.

The alt shop should have at least warned you to verify the wire/terminal purposes, or better -- looked at the two and alerted you which ones needed to be switched.  Good customer service (NOT!)  Find a new shop!

here's the two:

Transpo terminals:

__  I = BR - Ignition (key switch)
space
__ A = RD - Alt output - 12v+
__ S = Alt Stator                   __ Stator
__ F =  Alt Field                                            __ B- = Alt 12v- or ground terminal)

The Balmer:

                                                                    __ S = WH - Stator              __ Tach
                                                                    __ sense = Battery V
B- = BK - Alt 12v- or B- or GND terminal          __ B- = BK - Alt 12v- or B- or GND terminal
space
A = RD - 12v+ or B+ terminal
I  = BR - ignition - key switch
F = BL  - alt field


kk

[Analgesic]

Okay,  I get it.  I'm shocked (pardon the pun) that two regulators with the same 3 + 1 plug would be designed with the wires in different order, but that is clearly the case.  I have the wiring diagrams in hand and I think I'll be okay at this point.  Thanks again for all the help.

[J_Sail]

You should also consider the possibility that the mis-wiring may have permanently damaged the regulator.