Regulator/Rectifer 97 200 Merc carb

[TampaTom]

This is a new engine for me. Installed a new tach today and didn't seem to be getting a good signal. Traced the grey signal wire back to the top rectifer/regulator (2x20amp system). Switched to the loose grey wire on the bottom r/r and tach worked. So I'm guessing there is a problem with the top r/r or the part of the stator feeding it. I realize the proper method it to measure ohms and amp output, etc. However, I had another idea. Can I switch the yellow wires feeding both r/r's then test the tach signal from each unit? If I get a signal from the top r/r (which I'm not getting now), then I know the problem is the stator. If the top one still gives no signal and the bottom one continues too, then I know the top r/r is bad. Is there anything wrong with trying this? Will it be an expensive experiment?

 

[dilligafda]

Re: Regulator/Rectifer 97 200 Merc carb

Originally posted by TampaTom:<br />Can I switch the yellow wires feeding both r/r's then test the tach signal from each unit? If I get a signal from the top r/r (which I'm not getting now), then I know the problem is the stator. If the top one still gives no signal and the bottom one continues too, then I know the top r/r is bad. Is there anything wrong with trying this? Will it be an expensive experiment?

Answers to your questions, in order<br /><br />Yes, you can switch the leads.<br /><br />Correct, the problem would be the stator if that is the case.<br /><br />Correct, if the problem stays with the rectifier, then it is most likely bad.<br /><br />No, I do that in the shop whenever possible. Speeds up diagnostic time.<br /><br />No, the only expense will be if the reg/rec is bad.<br /><br />That is a common method of diagnosis in multiple systems like that. When all else fails, swap the suspect component with a known good part. Good luck and keep us informed!

 

[TampaTom]

Re: Regulator/Rectifer 97 200 Merc carb

Thanks Dilligaf,<br /><br />The problem appears to be in the upper regulator/rectifer as the tach only worked off the lower r/r regardless of which stator leads were attached (long or short yellow).<br /><br />Getting 14.5 volts at 1,500 rpm. Can I run for a little while with only the lower r/r (basically a 20 amp output)or could I damage something (like stator suppling upper r/r)by not replacing imediatly. I've been pourng too much cash into the boat budget this month.

 

[dilligafda]

Re: Regulator/Rectifer 97 200 Merc carb

The possiblity exists that you could damage the stator, more importantly though, you could have a short in the rectifier that could lead to a thermal event(volunteer firefighters don't like the "f" word). I would replace the rectifier as soon as possible.<br /><br />The choice is yours. Good luck!

 

[rodbolt]

Re: Regulator/Rectifer 97 200 Merc carb

hello<br /> yep but thermal events on the water way back the creek at the old fishing hole make memories . and they are way more exciting <br /> I would fix it but that is just me. look for blacked or burned looking connectors as well.<br /> good luck and keep posting