lost all electrical to the dash

[warrenw7805]

I have a 1978 starfire with the 470 mercruiser. While checking the boat out before heading for the lake, I discovered that I have no electrical to the dash or ignition switch. I do have power to the starter. There is also a wire coming off the positive post that goes to what I think is the power trim solonoid. I don't have a diagram to figure out which wires would go to the dash from there. It is pretty tight in there and don't want to just start pulling wires loose. Any ideas would be great. Also, where can I find the diagram on the internet for this? Thanks.

 

[Silvertip]

Re: lost all electrical to the dash

If you have no power to the ignition switch then how do you account for the starter working? Your diagnosis is not correct. Gauges are powered from the "I" terminal on the ignition switch so they go active only when the key is on. That terminal is then daisy chained to each gauge in the string. Same applies for the ground wire on the first gauge in the string. If the gauge requires a sender (as do fuel, temp, trim, and oil pressure) all of those have separate senders on the engine but none of them would prevent other gauges from not working. You apparently lost either +12 volts or ground to the first gauge in the string. Start there.

 

[CoffeeHound]

Re: lost all electrical to the dash

When testing --What are you using for a ground to the meter ??
if you have Starter voltage that is understandable because selnoid is grounded the the engine as is the starter .
I am betting on an open ground between battery and console -- let us know what you find !!!

 

[warrenw7805]

Re: lost all electrical to the dash

Thanks for all of the advice. I hope to have an answer this evening and will let you guys know.