For years tech guys required shutting off a running car with the master. I don't recall a lot of alternator failures doing that. Has something changed?

This is the New Good One! Moroso 74108

you run both the Battery & Alternator through it.

My alternator is wired through constant duty solenoid that closes when ignition is turned on so I am disconnecting alternator when motor is shut off and it has been fine for the past year, first year with it.

It's not just a rumor, I spoke to East Coast.Powermaster and Mechman about it. Alternator will continue to charge, what will happen is if you leave the power on to the alt and forget it the alt. will drain the battery. No one will say it happens every time but they will say it does happen.

Only time my alternator is hooked up to battery is when my ignition switch is turned on and master switch is also on, if either is off my alternator is disconnected from battery.

quote:

Originally posted by DragRaceResults:
This is the New Good One! Moroso 74108

you run both the Battery & Alternator through it.

See my post #5 from 2018 in this thread. It’s not new, it’s a rebranded cole Hersee 75912BX. No need to pay extra for the Moroso name.

quote:

Originally posted by 183N:
Originally posted by DragRaceResults:
This is the New Good One! Moroso 74108

See my post #5 from 2018 in this thread. It’s not new, it’s a rebranded cole Hersee 75912BX. No need to pay extra for the Moroso name.

Yup. You can see the CH logo right there in the center of the switch. (It's kind of upside-down, top of logo points toward stud at lower left). Great switch. Pricey, but reliable as heck, I put one on every one my cars.

Will this switch prevent killing the alternator as compared to a two lug switch?

Nope same theory, kills power to both car and alternator at same time.

So when using this 4 terminal switch on a dragster. i realize 1 setof terminals is battery in then out to starter. the other is alternator in. then where does the other terminal go? to the starter or do you use a jumper to the other output on the switch? my switch is at the back of the car on a rear engine dragster.

quote:

Originally posted by Andy5602:
So when using this 4 terminal switch on a dragster. i realize 1 setof terminals is battery in then out to starter. the other is alternator in. then where does the other terminal go? to the starter or do you use a jumper to the other output on the switch? my switch is at the back of the car on a rear engine dragster.

The other terminal goes to the battery. Picture the switch as two separate circuits. You have a switch between the battery and alternator and a switch between the battery and starter solenoid.

How I did mine was battery hot to one terminal and it’s “partner” after the switch went to the starter solenoid.

Then I made a short jumper wire to go from the hot side of the switch to one of the other terminals (so it would be the same as wiring it directly to the battery but without a second wire) then the terminal on the other side of the switch went to the alternator. So battery+ on two terminals, one out to alternator other out to starter solenoid.