Older 150 Merc Black Max idle problem

[j_martin]

Re: Older 150 Merc Black Max idle problem

Thanks, John. I've got a 1988 Mariner 135HP, and I am guessing it's the same setup. I have a spare regulator and rectifier, and thought my charging system was not charging my batteries. HOWEVER, some other electrical/wiring issues are resulting in my making a new instrument panel, new wiring harness, and re-wiring my entire boat, along with moving my batteries forward to the center console.

In my mind, I couldn't understand how you could charge the batteries without a voltage regulator. I guess removal of the regulator just puts full output on 'em, and as long as you don't boil 'em dry, they should charge up pretty good.

You got that one right.

BTW, I have switched from 16 amp to 40 and back (regulators fried) and then back to 40 (better regulators)

I find the Mercury 16 amp rectifier is a little Mesican T05 can pressed into an aluminum plate and potted in plastic or epoxy of some kind. The central unit is barely adequate, and thus they tend to be pretty short lived. If you acquire a 25 amp, 200V (believe me) bridge rectifier and wire it in, you'll never have any more trouble with it.