tach/rectifier question

morpheus847 · Aug 28, 2007

Im thinking i fried my rectifier the other day. Engine wouldn't start, solenoid just clicked. and before i would just get back there and cross it over and after it got warmed up it would start fine the rest of the day. Well i slipped off the terminal the other day and grounded it out for a second. Now my tach dosen't work. Thinking i fried the rectifier. Is it ok to run it if that's bad. If not is there anyway to hook up the tach strait off the strator to make it work. Also i read this will kill the charging system also. Ran fine last two times i've had it out. Anybody know how quick an outboard would drain a battery.

Barnacle_Bill · Aug 28, 2007

Re: tach/rectifier question

Year? Motor? If you caused sparks your rectifier is toast.

HighTrim · Aug 28, 2007

Re: tach/rectifier question

The rectifier converts the AC from the stator to DC which allows your tach to get a reading. If the tach is faulty a bad rectifier could be to blame. You didnt mention what motor you are referring to , I could post a rectifer test for you.

oops, type too slow

ezeke · Aug 28, 2007

Re: tach/rectifier question

edit

Barnacle_Bill · Aug 28, 2007

Re: tach/rectifier question

The tach actually works off AC pulses from the stator. Those same pulses feed the rectifier so thats a convient place to make the connection. Thats why you have to set the tach for the no. of pulses coming from the stator. Once rectified it no longer pulses. Well it does a little because there are no filtering circuits (big capacitor) in the circuit. Its just raw DC and the battery doesn't care.

jtexas · Aug 28, 2007

Re: tach/rectifier question

downside to running with rectifier disconnected is, it won't charge the battery. it won't harm anything.

try this: disconnect, clean, and reconnect all the cables/wires from battery to solenoid to starter, I mean make 'em shine. And tight! see if that doesn't clear up your solenoid problem.

morpheus847 · Aug 29, 2007

Re: tach/rectifier question

sorry forgot to put that in there it's a 1982 90hp evinrude model e90tlcnb. I was thinking it was like a car if it's not charging and battery goes dead so does the motor hmm anyway. I don't think i would have to worry about it then, all my electronics are running off my deep cycle battery and i usually charge it after every outing. So what im understanding is if i take the rectifier out of the curcuit my tach should work again right. And then just keep an eye on my starter battery. That's the only thing thats on the motor battery is the starter and tilt/trim.

morpheus847 · Aug 30, 2007

Re: tach/rectifier question

Well figured it out believe it or not. Rectifier was good. Week before i hooked all my accessories up on a seperate deep cycle battery. That's when it quit but i didn't really think about that where i had grounded it out. Put a ground wire coming from my deep cycle to my starting battery and it works again. Must not have been able to find the pulses coming off the motor where they were grounded seperate. This should be alright im thinking. Both batterys should still just be putting out 12 volts a peice. There just grounded together right.

HighTrim · Aug 30, 2007

Re: tach/rectifier question

Do you have a battery selector dial to switch between batteries?

HighTrim · Aug 30, 2007

Re: tach/rectifier question

here is an example

Gary H NC · Aug 30, 2007

Re: tach/rectifier question

If the rectifier is bad why not spend the 20 or 30 bucks and fix it right?
The 3 wire one for my 175 was only 20 some bucks.Now my battery charges great.

morpheus847 · Aug 31, 2007

Re: tach/rectifier question

from what i can tell the rectifier is good. or else my tach wouldn't be working would it. I think the tach ground just has to be tied in with the same ground that the motor is on. and since i hooked it up on a seperate battery it wasn't doing that.

Barnacle_Bill · Aug 31, 2007

Re: tach/rectifier question

If a diode in the rectifier opens your tach will still work. Normally they short and that kills the tach. Power and ground should go to the starting battery.

jammer · Sep 2, 2007

Re: tach/rectifier question

morpheus847 said:
from what i can tell the rectifier is good. or else my tach wouldn't be working would it. I think the tach ground just has to be tied in with the same ground that the motor is on. and since i hooked it up on a seperate battery it wasn't doing that.

You could be right. Want to make sure though? For me you see..if one thing works...I personally never assume anything anymore concerning boating...I test it. I would recommend either a nice volt meter guage. Or test it with a volt meter and run the engine. See if you are getting like about 14 volts or higher reading on your battery. Then you know for sure it is charging.

tach/rectifier question

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