Mercruiser 120 Instrument wiring

[Cfkdaddy]

Hello, I have an early 70s Mercruiser 120 that has some wiring issues. I am looking for a picture of the back of the instrument panel that shows how its wired up.

Specifically, I have a purple and white wire that is attached on the instrument panel, but is cut at the wiring harness. Im trying to figure out where that should go, and why it was cut.
Also if anyone has a picture of their ignition key setup, that would be great. I had to buy a new ignition because the old one was completely broken. Im not sure I have it wired correctly.

Much appreciated!

 

[Scott Danforth]

the gauge schematic is in the factory service manual for your motor.

a serial number will help.

 

[Scott06]

Hello, I have an early 70s Mercruiser 120 that has some wiring issues. I am looking for a picture of the back of the instrument panel that shows how its wired up.

Specifically, I have a purple and white wire that is attached on the instrument panel, but is cut at the wiring harness. Im trying to figure out where that should go, and why it was cut.
Also if anyone has a picture of their ignition key setup, that would be great. I had to buy a new ignition because the old one was completely broken. Im not sure I have it wired correctly.

Much appreciated!

down this thread has two versions of a similar vintage merc helm wiring no purple and white, but there is a red and white (possible its faded?)associated with the key switch

Dwell on a mercruiser 165?

forums.iboats.com

 

[achris]

Hello, I have an early 70s Mercruiser 120 that has some wiring issues. I am looking for a picture of the back of the instrument panel that shows how its wired up.

The wiring on most boats of the vintage have been so butchered over the years that it's almost quicker the trace out and draw up your own writing diagram.

That said, that era produced a lot of different wiring variations. We'd need to know a lot more specifics about the instrument panel and engine than 'early 70s MerCruiser 120'. Does the instrument panel have a voltmeter or an ammeter? It's there a big red light in the instrument panel?

Chris...

 

[Cfkdaddy]

It has an ammeter on it. Here is a picture of it as well as the back. No warning light that I can see. No breaker switch either that I have seen on some of the 120s and 140s.

 

[Cfkdaddy]

I also really appreciate the help I am new to this and trying to educate myself as fast as I can. This is a lot.

 

[achris]

This is probably the diagram you're looking for...