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charging system voltage regulator

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chevy83m

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Hello i have a 87 mercury xr2 150hp black max. I need info on where to hook up the two wire voltage regulator i can find wiribg diagram for it anywhere. The voltage regulator has two brass bolts for a two wire lead to attach (red and a yellow) wire. Any help would be great thank. The engine charges but im not sure it should charge more then 14 volts.. Thanks again
 
are you sure you are looking at the regulator?is this part you are trying to put on identical to the one you are replacing?that motor has a rectifier only voltage regulator with a minimum of 4 wires...
http://www.maxrules.com/mercwireindex.html
this is a place to start...

if you have a rectifier only system,which you probably have,then the voltage output is unregulated and will exceed 14 volts...if you put a maintenance free battery on the engine it will exceed 16 volts and eventually damage the rectifier..you need the old style battery where you add water..
 
I've seen rectifiers allow charging voltages close to 18 volts at high engine speed. This is why it's not suggested to use automotive batteries on outboards without regulators. Automotive batteries are more prone to damage from overcharging than deep cycle batteries. It's an easy update to switch to a rectifier/regulator. Attached is before/after pictures of my Mariner I6. Original rectifier is on the top and the rectifier/regulator I added is mounted under the starter. I selected a rectifier/regulator from a newer model Merc. Works perfect and limits charging to 13.8V. Also safer if you have any electronics.
IMG_1299.jpg


chevy83m said:
Hello i have a 87 mercury xr2 150hp black max. I need info on where to hook up the two wire voltage regulator i can find wiribg diagram for it anywhere. The voltage regulator has two brass bolts for a two wire lead to attach (red and a yellow) wire. Any help would be great thank. The engine charges but im not sure it should charge more then 14 volts.. Thanks again
Click to expand...
 
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Its not automotive vs marine that's the problem...there are other advantages of a marine battery that I will not get into..it is the sealed batteries. either marine or automotive, that you don't want to use with a rectifier only outboard charging system..

there are many theories on what happens...the one I go by is this: a battery that you add water to is an older design..it is somewhat self regulated by an internal discharge if over charged..the sealed maintenance free batteries do not have this...we also hear this on here occasionally:''the battery says maintenance free but has removable caps''..it don't matter..if it says maintenance free then that battery will go to 16volts and above on a rectifier only system....

the failure sequence is that the tach gets erratic...you look at the voltmeter and the voltage is well above normal...if you continue to run it then sooner or later you have no tach and you look at the voltmeter and all you have is 12.x and the rectifier is shot...if you just replace the rectifier it will fail again..it may be a say or a year or more but it will fail..your electronics are exposed to this high voltage..your stator may be running hot due to excess current and that's an expensive part..

good neat job Ed Cz...that's the route to go although picking a regulator to install that is not designed for that stator may be dangerous...there are current draws from the stator to consider...
 
here are the parts listings for a two wire voltage regulator from marine engine. com no wiring schematic though. my xr2 had a rectifier and separate regulator. I should have just paid more attention to where I un hooked it from. the regulator mounts up by the flywheel with two small Phillips screws
 

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Mine has a regulator and rectifier. Look up the 0b122495 serial number on this web site. I tried to upload picture but it wont.
 

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It mount's on top of the block right behind the rear cowl bracket.Make sure it a metal to metal contact. Wire it with red from reg to red on rect an yell from reg to either yell on rect.
 
I cannot find a wiring diagram for that serial number either...does the rectifier have 3 posts?the two yellow wires on the input..the red on the output...the grey if you have it is your tach and can go on either of the red wire post or either of the yellow wire posts..i have saw in the past diagrams with an add on regulator but I cant find them this morning...nor does the parts list above include it...maybe someone can step in that has a diagram of the add on regulator...
 
thanks faztbullet...I had the thread up and was on the web for a long time and didn't see your entry til after I posted..
 
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