Tach and charging system not working

[imported_Z]

Johnson 1990 175HP STLES

I am having problems with both my charging system and tachometer. After researching similar problems posted here I ran the Joel Reeves water cooled rectifier test. After verifying the continuity of the gray wire on the back of the tach and the grey wire at the terminal strip, I took the gray wire off the terminal and connected it to the yellow/gray wire on the terminal. When I did this I fully expected the tach to work and point to the rectifier. It still didn't work. Next I took my multi-meter to test the voltage of the battery - 12.67 - started the engine and voltage remain basically the same. I expected it to go up to around 14+ volts. The voltage meter on the boat also reads around 12 volts.

I guess it's possible that both are faulty. Are there other tests or steps that I should be looking at.

 

[imported_Z]

Re: Tach and charging system not working

Thought I would try again to see it anyone has any ideas. Thanks.

 

[Barnacle_Bill]

Re: Tach and charging system not working

Shorted diodes in your rectifier will keep your tach from working.

 

[imported_Z]

Re: Tach and charging system not working

I agree, but my understanding was that when you run the test identified in my post, the tach should register and it didn't. Maybe both are bad, but before I make any investments, wanted to test it out and know definitively.

Thanks for your reply.

 

[tashasdaddy]

Re: Tach and charging system not working

http://forums.iboats.com/showthread.php?t=190638

http://forums.iboats.com/showthread.php?t=190636

 

[Boblester40]

Re: Tach and charging system not working

If the diodes have totaly gone it will completely ground out the charge coils which would give you no tach signal were ever you connect to .

rgds
bob

 

[imported_Z]

Re: Tach and charging system not working

when I do the water cooled rectifier test, I get no response from the tach. I located the wire and verified it led to the tach, connected it to the yellow gray wire, nothing. Even tried the yellow wire, still nothing.

I guess the rectifier is toast. On the smaller rectifier test that Tashasdaddy sent, you can run an Ohm test to verify is its bad, can the same be done on the water cooled versions?

I hate to throw parts at something with out knowing for sure.

Thanks all for your replies.