150hp Merc rectifiers.

xsportz98

Recruit
Joined
Dec 20, 2004
Messages
5
Hi again. I finally got a chance to check my overcharging 1993? 150 Merc (serial number OG129931). Firstly, I found that there is 2 square rectifiers under the coil mounting brackets, is this normal? The boat shop said that there would be one. I searched back through this forum and found to test a 2 regulator system I should disconnect the yellow wires from each individually and compare voltage at battery. results are as follows: bottom disconnected-14.5 at idle, 14.5 at approx 2500rpm. Top disconnected, 14.8 at idle, 15.8 at 2500rpm....smoke then come from the lower pack (connected one). I removed the packs and found that the lower ones clear insulating material was blackend!<br />So, finally, my questions are: Do I need to replace both packs at once? What voltages should I be getting in the above tests? and finally, does somebody have a part number for these packs as the ones on them are smudged and I cannot find them on the web on any diagrams. Thanks again...<br />Ps the Marlin are on.... I need to get this thing going!
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: 150hp Merc rectifiers.

They have been replaced with a better unit. It has black potting and a ground wire. I liked the clear green potting because you could usually see if the unit had blown. With the black potting it's not nearly so easy to tell. I have no idea why they would've told you it only had one.<br /><br />If the current that's being produced suddenly has no path anymore, it'll make one inside the regulator. Loose battery connections can cause that. Chances are that is what fried one or maybe both.
 
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