1975 mercruiser 165 starting issue

[Rumley]

My engine won’t start. Just clicks. Batteries are good. I read to jump starter solenoid but I’m not sure which 2 wires to jump. Including a pic of what I think is the solenoid. Any help much appreciated.

 

[Scott Danforth]

Start with cleaning every battery cable terminal connection, both positive and negative

 

[alldodge]

Cross these two shown should energize the relay and the starter should crank the motor. If this does not happen, you can jump across the larger terminals on each side which by passes the solenoid. Doing it this way will pull a lot more current, so if done use large cables

 

[Rumley]

So cross the 2 with the key in the run position with the 2 blue arrows?
if that doesn’t work a booster pack on both of the large posts with key on?
thanks

 

[alldodge]

So cross the 2 with the key in the run position with the 2 blue arrows?

Yes

if that doesn’t work a booster pack on both of the large posts with key on?

No

If that does not work use jumper cables to connect between the two large post to bypass it

 

[Scott Danforth]

Use the biggest screw driver you own when jumping the two large contacts, or a short section of 2 gauge cable

However start with cleaning all the connections to shiny clean metal