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Master Battery Cutoff Switch with Alternator Protection

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We carry the highest quality master battery switches available. This competition-proven switch is rated for 100 Amps continuous duty and 500 Amps peak current. (See note below on how to spot a lower quality clone.)

This switch has three sets of contacts for cars with alternators. The main contacts disconnect the battery while the auxiliary contacts disconnect the ignition coil and short the alternator output to ground. A 3 ohm resistor (included) provides a load to protect the grounded alternator. A removable actuating key with splash guard, weather-proof cap, resistor and installation instructions are included. (Resistor lead configuration may vary from the photograph shown.)

Question: How do I know if I'm looking at the genuine article and not a lower quality clone?

Answer: The terminals of the genuine highest-quality switches are plated with a tin-alloy and are therefore silver colored. Lower quality clones have unplated brass terminals. In addition, genuine switches are shipped with half-height nuts while clones are usually furnished with full height nuts.

Over the years we've heard about dozens of DNF's caused by unreliable master battery switches that were purchased elsewhere. Is saving a few dollars worth risking a DNF?

Recommended accessories, sold separately:
"Off" Decal (Part No. 3356)
Master Switch Mounting Tab (Part No. 4375-001)

Wiring Instructions for 4430 Master Battery Switch

Part No.
Stock Status

Condition: New

In Stock

Great product


Great product. Good quality. Install is not for beginners but not complicated.



Decent switch, horrible directions


Good cutoff switch, but the directions are useless.

Trevor Shand

Charlottesville, VA


Dealer of choice


Pegasus was my supplier for several years until I quit racing. I'm currently helping the next generation get started, hence my recent purchase. I am pleased to say that as Pegasus has grown since my first purchases in about 1990 the customer service and shipping has maintained the quality I remembered. I'm pretty sure you have already locked in the next gen.


MN and FL


As Advertised


Heavy duty master switch used in Corvette C5 and does the job as advertised.


Dallas, Texas


Spend a few more bucks and get the best


I was so pleased with the first Master Battery Cutoff Switch with Alternator Protection to use in our track car that I purchased another to use in a 1937 Ford Pickup Restomod project. GREAT PRODUCT!!

Little Green Truck

Port Townsend, WA


Quality like everything else here


I will buy all of my important parts from Pegasus because its like a candy store for anyone who races. This switch feels solid, and the instructions were very easy.


San Diego, CA


No One Is Hot-Wiring My Race Car!


Thanks, Pegasus, for carrying this Master Battery Switch with the BIG red key! I'm in the process of putting a 120 Hp Formula V on the street, and finding specialty Formula car items isn't easy. But I always start searching at your website and 99.9% of the time I find exactly what I'm looking for. This switch with the BIG red removeable key will compliment the motorcycle audible alarm system, making my racer virtually theft-proof.


Lake Arrowhead, CA


Carried as a spare.


Carried as a spare incase we need it.


Sayre, PA


As good as you can get.


The major upgrade to a car from the mid 60's is the electrical components. The Dyno has been replaced with a generator and the master switch is the best available.


Nashua, NH


Solid switch, easy to install


Bought this for my 24 hours of lemons car. Diagram was easy to understand and installation went simply with the purchase of the mounting plate. I put it neatly in the driver a/c vent.


NYC, NY, United States


Master Battery Cutoff Switch with Alternator Protection

4.9 10