I have a 96 Powerplay 28 with a single HP500. I have all of the original Gaffrig gauges still. Since I have bought the boat the tach has rarely ever worked. It occasionally kicks on, but is broke 90% of the time. The water pressure gauge also does not work, and is a recent problem.

I have noticed when cranking the tach will move, and also just saw when adjusting the trim tabs it will flicker as well. I'm not too familiar with rigging, etc, but this kind of seems like a bad ground problem? If that is it any ideas where to start looking?

If it's not a ground, any other ideas of what it could be? I'm not sure if maybe it's just the tach is bad, but the way it occasionally works and flickers when moving tabs/cranking makes me think its not that.

Any help is appreciated.

I'm guessing it's a bad ground. Check the back of guage first, then check out all the grounds on back of block. Yours should be pretty close to mine and it should be easy.

I haven't checked the grounds on the block, I'll try there, thanks.

Get a test light or meter and look for power and ground at the guage. If you see power and ground and the lugs are tight then look at your tack wire. Make sure it has good connection at both ends. If all that looks good, while you have the boat idling have some one watch the tach and move the connectors around. Especially the one at the engine. I had one of those plugs be bad once and my tack did not work. I was able to crimp the connector in the plug and fix it. If all that does not help then run a new wire from the engine to the back of the tack (you have to remove the old tach wire at the back of the tach first). If you do all that you will eliminate all wiring as the problem and then will know it is the guage. It sounds like a lot of work but should only take you about a half hour.

I wouldn't be too surprised if it is a plug I guess, as it works very randomly like when it gets bumped right. Thanks.

If ya need a hand let me know! I've been all through mine...
586-260-4359 I'll be available Sunday

Thanks man!

I plan to take it out Sat and go through it out on the water (a lot more fun than on a rack!)

I might give you a ring Sun if I'm stuck still.