Electrical question

[pstephens46]

Examining the starter relay on the F150 today. Never really looked at the wires very closely that are connected to the lugs. The amps that cross that relay, as I understand, are 150-200. How can those wires be 10-12 gauge? The relay controls the ground, correct?

[boscoe99]

On your F150 the starter relay does not power the starter motor. The relay provides power to another relay that is part of the starter motor itself.

A bit of current flows through the starter relay. A lot of current flows through the relay that is on the starter motor.

[pstephens46]

On your F150 the starter relay does not power the starter motor. The relay provides power to another relay that is part of the starter motor itself.

A bit of current flows through the starter relay. A lot of current flows through the relay that is on the starter motor.

Wow. And that now makes sense. Thanks

[ausnoelm]

I don't think it makes a lot of sense to have a relay to run a relay, kind of like having two light switches for a light, and both need to be switched to power the light.

[boscoe99]

I don't think it makes a lot of sense to have a relay to run a relay, kind of like having two light switches for a light, and both need to be switched to power the light.

Quite commonly done in order to reduce the size, expense and weight of electrical wiring.

I suspect that one day just one relay may be involved that is con*****ed wirelessly. I would like to see that today in a control box.

[fairdeal]

I don't think it makes a lot of sense to have a relay to run a relay, kind of like having two light switches for a light, and both need to be switched to power the light.

of course some (but not all) starters combine the final electrical relay function
with the mechanical extension of the starter pinion gear

[TownsendsFJR1300]

There's a relay on my F150 under the plastic cover (port side) and I've replaced it once:

Part # 4, https://www.boats.net/catalog/yamaha...1/electrical-2


Both main battery cables go to the block (ground) and the positive to the starter solenoid -
The solenoid is called a starter RELAY by Yamaha, part #22: https://www.boats.net/catalog/yamaha...starting-motor There is NO SWITCH / contacts inside that unit.





My burned up contacts inside the #4 relay that failed:

[TownsendsFJR1300]

The starter and solenoid are wired direct from the battery:


Part #22 the solenoid: https://www.boats.net/catalog/yamaha...starting-motor is called by YAMAHA A RELAY. There is no switching contacts (relay) inside the starter solenoid.




The separate starter relay (under the cover) part #4. My contacts burned up:

[boscoe99]

of course some (but not all) starters combine the final electrical relay function
with the mechanical extension of the starter pinion gear

The OP's starter motor for instance.

[TownsendsFJR1300]

I keep getting blocked from posting but YAMAHA CALLS the above, part #22 a starter solenoid a RELAY. which is not a relay.

There are NO on/off contacts inside the solenoid.

The starter relay is the one under the plastic cover, port side...(which I've replaced before)

[TownsendsFJR1300]

With a bad starter relay, you may still hear it click when activated, but when the inside contacts are burnt, full electrical power isn't able to make it to the starter.



My burned up contacts inside the ACTUAL starter relay:

[boscoe99]

Relay, electrical solenoid, contactor, etc., call it what one will. Semantics.

Can a switch be used as a sensor and be known as a sensor or is it always and forevermore to be known as a switch?

It appears that within the starter motor assembly there is a coil that when energized closes a set of electrical contacts that allow a large amount of electrical power to flow from the battery to the starter motor brushes. As opposed to the set of contacts in the starter motor relay that allow a small amount of current flow from the fuse block to the starter motor relay. Or electrical solenoid is one wants to use that term.

[boscoe99]

Nother view of the system

[walleye1]

What is a slave solenoid?

[boscoe99]

What is a slave solenoid?

I would say that it is a solenoid (mechanical or electrical) that works at the direction of its "master". A master solenoid if you will.

Comparable to a slave cylinder and a master cylinder in a hydraulic brake system. The master applies hydraulic pressure to the slave cylinder to make the slave do the real work. Whereas a master solenoid provides electrical pressure to its slave solenoid.

Where is this all heading?