Anyone have a wireing diagram for a 311. one of my temp guages it not working and did some plem checks and ran across something a lil wierd.. On both engines there are 2 senders in the outlet hsg, one of them has battery voltage going to the sender on the engine with the guage that is inop. ?? On the other engine the one wire has 8.6v going to the sender..

Ohh and I have the Gaffrig redline guages.

I would love to find a complete wireing diagram for this boat if anyone has any idea where to locate one.

Thanks,
Adam V

I would contact Formula, they had one for my boat and just e-mailed it to me. Even if they don't have the exact year, they will have one close.

I have the wiring Diagrams but they are difficult to read ...poor quality ...I also have the 312 diagrams which are good quality .....email me ...

actually pretty simple .... Tan is water temp ...blue oil pressure and tan/blu is alarm ... should be two senders on the intake ....one is temp ....other is alarm ......m


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That is about what logic told me, but why would i have battery voltage on one and 8.6v on the other, which i am assuming are the alarm wires?? beacust the sence wires going to the guage shouldnt have that much voltage to them should they?

I called Formula and they said they didnt have any diagrams that old, mine is an 88 311.

The senders just serve as Ground ....the gauges have the positive side and you are reading the resistance of the Gauge or the Alarm .....

I have a book for my 357. I looked through it, but the info you need is not there. I do have a Mercruiser High Performance Series service manual I purchased on ebay. Everything you need to know about your engine package is in there, that's where you'll find the wiring diagram. Formula only covers the boat electrical systems. Most shops will have it, hope this helps.
BC
If you can't find anything, send me a pm and I'll copy and send you what I have on the boat systems, I'm sure they are wired the same.

diagrams ....Basically all the same .....

Either swap sending units or ...pull both wires off the sending units and put a jumper from from the engine where the gauge works to the engine that doesnt ...