Re: 1996 Mercury 135hp Voltage regulator repair?
Thanks for the quick response tip. I could do that switch to the good reg myself and save the $55. I suspected that was the repair he was going to do. But doing only the tach wire switch and not replacing the bad reg I'd only have 20 amps of total charging instead of 40 amps correct? Can that bad reg still have good dc output just not tach voltage? I've got a lot of electronics drawing off the starting battery, even though I have a onboard battery charger that is a three bank that charges the start batt. would it be better to replace the one bad reg now and replace the other if it fails later? Or will one bad reg take out the other in time? Thanks for your expert information............Steve
When the tach goes, the regulator is almost always shot.
Move the tach wire to the other one and see if it works. If it does, disconnect the first regulator (tape off both the red and yellow wires) and go looking for replacements. You can run on 20 amps in the meantime.
New, I'd go CDI. Used, look for the black 6 wire mercury regulators with the black potting. They're pretty good too. You can replace one at a time. It shouldn't be a problem, even if the other one goes later. If you have a pretty good load, like lots of electronics, or you anchor and run off the battery for long periods running the battery down, theoretically shouldn't hurt a single regulator. Only problem is the regulators can't read or understand theory.
Often the yellow wire (stator) bullet connectors relax and heat up, and the heat travels down into the regulator and stresses it. Fix is to at least replace the connectors. I solder and shrink wrap the connections.
hope it helps
John