43L 2004 Glastron Tach problems

"Hi All...
I have a new

"Hi All...
I have a new to me 2004 Glastron SX 195 with a mercruiser 4.3L carb. engine. The tach is eratic to say the least. When the egnition swith is turne to run, the tach "pegs out" however once the engine turns over it flat lines at zero. As long as the boat is runing, the tach never moves. However, once the engine is turned off (after ideling forever and a day to keep from "running on" which I hope to ask about as well) the tach pegs again. Let me say that I am not the most mechanically inclined individual and purchased the Seloc manual (online version) today with hopes of repairing both problems (tach and run on). After spending most of the day searching, I found the manual was not quite the key to solving my problems. Please don't take this as a put down to the manual, I believe as my skills grow the manual will prove it's worth many times over, but for these specific problems it just didn't have all the answers I was wanting. I know I am "running on" myself but this is my first boat and my family and I truely are enjoying the boating life. I just want to ensure we get the most out of our time and money spent for some desperately needed family time. Any suggestions are gladly accepted."

"Sounds like the wiring to you

"Sounds like the wiring to your tach may be flakey, or you may need a new tach.
Rod"

"Rod,
Thank you....I rem

"Rod,
Thank you....I removed all the wiring Friday night and re-connected everything trying to ensure no light connections. I then turned on the ignition but did not start the motor since I didn't have the "ear muffs" on. The tach did not move. However, when we launched Saturday the tach was dead. I'm guessing at this point the tach is fried and will need a new one."

I'd say that's a prett

I'd say that's a pretty good bet.
Often when a tach goes on the blink it interferes with the entire ignition system and sometimes the engine won't even start.
Rod