new recticifire gone bad?

89renken175

Cadet
Joined
Feb 1, 2012
Messages
13
I have an 89 e175txceb and put a new CDI stator and rectifier on May 2012. Ran great until fall of 2013 when tach stopped working and not showing a charge on gauge. Battery was replaced in March 2010.
No, l have not pulled the positive cable off battery while she's running. I heard that will fry a rectifire.
What are the chances of rect. Being defictive.
I hope I don't have to buy a new rect. any help would be great... Thanks
Note.. The tach stopped working before charging issue.
 

nphilbro

Petty Officer 1st Class
Joined
Dec 19, 2011
Messages
304
Re: new recticifire gone bad?

I had one go out on a 1983'ish 140hp once. It was a bit more intermittent at first, though. Not sure the cause. I checked resistances and voltages to other components and those not affected to/from the rectifier were within spec so I replaced it and all was fine after that. Mine had the terminal block screws on the side so I could change which yellow wire the gray (tach) wire bridge to. Since the rectifier is nothing more than an electrical gate that allows only a selected part of the current through I was surprised when the tach worked attached to the other yellow wire. However, it failed in a few weeks that way too so I'm not exactly sure what logic they use and what they filter. When connected to AC voltage, a diode will allow only the + portion (1/2) of an AC sine wave through and block negative polarity and a logic gate will pass the positive from both sides of the cycle so I'm not real sure what else is going inside since it should fail regardless of which yellow lead it's connected to. I've never looked for a schematic since it was fixed after that.

Like I said, I replaced it and it was still working when I sold the motor the following year. I hate throwing new parts at a symptom too.
 
Last edited:

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: new recticifire gone bad?

That engine has the 35 amp alternator. It does not take a rectifier only. Hopefully, you replaced the combination rectifier/regulator assembly in May of 2012. They can go bad if the battery terminals are not tightly clamped while the engine is running. I'd agree, once the tach stops working, likely the combination rectifier/regulator may need to be replaced. I know the factory parts have a one year parts warranty. Have no idea about CDI part warranties.
 

nphilbro

Petty Officer 1st Class
Joined
Dec 19, 2011
Messages
304
Re: new recticifire gone bad?

That engine has the 35 amp alternator. It does not take a rectifier only. Hopefully, you replaced the combination rectifier/regulator assembly in May of 2012. They can go bad if the battery terminals are not tightly clamped while the engine is running. I'd agree, once the tach stops working, likely the combination rectifier/regulator may need to be replaced. I know the factory parts have a one year parts warranty. Have no idea about CDI part warranties.

I believe you're right, EMD - it was a while ago but I'm sure right about it being a combo unit, now that you mention it.
 
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