Simple Disconnect For Street Cars

We mounted the Disconnect nearly out of sight just below the battery on the driver’s side wheel well. This way we were able to use the existing battery cable. Note that there is a fuse to protect the solenoid in case there is a short in the wiring.

When you park your muscle car during the week, do you disconnect the battery cable? Think about it. Chances are that most of that wiring is three to four decades old and has been modified or hacked into more than several times. And your car is sitting there with voltage just looking for a place to jump to short or jump to ground.

Even if you have rewired the car, the chances of a short or problem in your wiring harness that could result in a fire is, in most cases, slim. However, after a weekend of cruising or some fun drag strip abuse, connections can vibrate loose, heat can melt through sleeves or circuits can simply break apart. By simply disconnecting the battery all together the chances of fire are slim to say the least. But opening the hood or trunk, getting a wrench out and scarring up your battery terminals can be a hassle.

Painless Performance offers a heavy duty Remote Master Disconnect Kit that makes disconnecting the battery’s power as easy as flipping a small toggle switch. Simply install the heavy duty solenoid/relay assembly on the battery positive cable before the starter solenoid and mount a small toggle under the dash – instant power kill! The relay is capable of carrying up to 250 amps continuously so there should be no trouble with a multitude of electronics or cranking.

The solenoid is the part that is responsible for physically opening the circuit. The trouble is having a control that allows you to switch the solenoid so it is on (closed) or off (open). That is where a relay comes in. A relay is a handy device that allows a switch with a small amount of current to control a circuit that uses a lot of current.

Painless supplies enough wire to mount the switch just about anywhere you please. We opted for the glovebox. One side of the toggle switch connects to the relay, the other side simply connects to ground.

It is important to note that this kit does not pass for a legal cut-off switch such as the ones required in drag racing. It simply serves as a safety switch or even as a theft deterrent for your car and is extremely helpful in cases where the battery is in mounted in a hard to access position.

Our installation took about an hour and has given us a peace of mind when parking the car overnight or during a long storage period.

This diagram shows just how easy the Disconnect wires. The solenoid has a built-in relay which is the reason that you can disconnect high current through a little switch mounted inside the car.