Minor tach issue

[NCrunner2012]

Hey everyone,

I have a '93 stingray 606 with the 4.3 mercruiser and alpha 1. I have a couple minor issues I was hoping maybe to work on before boat season.

My tach rises to 1500 rpm when I turn off my ignition. It instantly drops to 0 when ignition power is restored and works normally as far as I can tell. I'm thinking possibly a grounding issue there maybe you guys have some more input.

 

[GA_Boater]

I don't think you have a problem. Has it always done this?

 

[Bondo]

It instantly drops to 0 when ignition power is restored and works normally as far as I can tell.

Ayuh,.... Welcome Aboard,.... That's not unheard of,...

I agree with GA, you don't have a problem,...

 

[achris]

Hey everyone,

I have a '93 stingray 606 with the 4.3 mercruiser and alpha 1. I have a couple minor issues I was hoping maybe to work on before boat season.

My tach rises to 1500 rpm when I turn off my ignition. It instantly drops to 0 when ignition power is restored and works normally as far as I can tell. I'm thinking possibly a grounding issue there maybe you guys have some more input.

Proper marine instruments are 'unsprung' and will seek their own 'happy place' without power applied. Having all the gauges (expect the voltmeter) 'float' to random readings once the power is off is completely normal.... Once power is restored, the gauges read what's coming in. If it's a tacho, it'll read 0 until the engine is running. Something else you may see, and it is again completely normal, is as you're cranking the engine, if the battery is down a bit, the needle will start 'spinning' all over the place.... Again, nothing to worry about.... It'll all come good when normal 12 volts is restored...

Chris........