Why is there a relay after the start in gear protection switch

[workmaster2n]

After nearly 2 years, I finally solved my troublesome engine starting issues. Turns out there is a lockout on my throttle quadrant to prevent starting the boat while in gear. It's a simple momentary switch that is engaged when in neutral but open when in gear. A bit downstream from the switch is a relay. The circuit goes ignition switch, momentary switch, relay then to the loom that goes to the engine (where there is another relay before the starter motor solenoid at the engine).

The relay immediately downstream of the gear lockout switch had fried itself, so simple fix.

The relay before the starter motor solenoid I understand, because it's a fairly long run for the ignition signal to travel down, so the relay enables a 12v signal that has dropped a bit over this run to fully engage the solenoid. I'm not sure what the point of the relay downstream of the lockout switch is for. Presumably the same thing?

[workmaster2n]

I was able to get hold of a local dealer, and they said that some installers will use a lower amperage circuit to feet the momentary switch, and then need to boost back up to a higher amperage before sending the signal down the loom, hence the relay.

Totally makes sense.

[deblen]

Originally Posted by workmaster2n

I was able to get hold of a local dealer, and they said that some installers will use a lower amperage circuit to feet the momentary switch, and then need to boost back up to a higher amperage before sending the signal down the loom, hence the relay.

Totally makes sense.

Or/and... You do not want any power going to starter solenoid(relay 3)coil unless shifter is in N..

so you don't want Relay 2 coil operated & passing power thru it's contacts to the coil of Relay3...
so you insert a momentary switch in shift mechanism. It only closes it's contact & passes power to relay 2 coil,when momentary switch is mechanically activated in the N position.


Shift to N & turn key to start position. The momentary switch is "turned on" by a cam at N.
Power from the key turned to start position passes thru the now closed contacts of the momentary switch and reaches the coil of Relay 2.
Relay 2 operates & passes (probably Hvy duty) power thru it's contacts to the coil of Relay 3.
Remember-relays have a coil that requires power. They also have contact(s).
Operating the Relay closes Normally Open (N.O.) contacts & opens Normally Closed (N.C.) contacts.
Very usEful buggers! Hope this helps
Cheers/Len