Properly wiring high-draw accessories like electric fans requires using a relay, but many hot rodders get cheap or lazy and don't bother running them. However, tapping into an existing circuit instead of using a relay can result in poor accessory performance and compromised reliability. So how do they work and when do you need them? "Relays are high-current switches that are remotely activated. The purpose of a relay is to switch high-current devices like electric fans and lights, thus preventing premature failure of the controlling switch," Dennis explains. "Any device that requires a current load of 10 amps or more should always have a relay in its circuit. A standard toggle switch can only handle 10-15 amps max. That's why toggle switches burn up so quickly when you use them to activate electric fans. By taking the brunt of electrical current, relays designed to switch high-current accessories can handle up to 70 amps."
Screw connectors, soldering, and crimps are common methods of joining wires and terminals together, but they can all work themselves loose. As far as Painless Performance is concerned, for a durable connection it's tough to beat a good crimp. "Most people would think soldering is the way to go, but I am a believer of crimp terminals. If a professional is soldering and using heat shrink, then the joint will last a very long time, but the average person rarely uses a soldering iron correctly and isn't proficient at making good, solid joints," Dennis opines. "When soldering, overheating the copper strands, making cold joints, and causing the copper to get brittle can shorten the life of a joint. A good crimp joint can last forever. A messy solder will create more problems than it solves. Keep in mind that GM does not solder wires and crimps. Another benefit of crimping is that the joints have more flexibility than a solder. To crimp a wire, first strip it to correct length for the terminal it will go into. You should just barely see the copper sticking out the ring or the fork. The terminal should be secured on the wire, but don't squeeze it too hard and mash it up."
Engine Swap Harnesses
Late-model vehicles have very complicated factory wiring systems that can be a bear to work with when swapping a newer EFI motor into a muscle car. Cutting and splicing is par for the course, as is sifting through wiring diagrams to figure out which wires are needed and which ones aren't. Fortunately, opting for a Painless Performance engine harness eliminates the hassle involved with modifying a factory harness in an engine swap application. "Each Painless engine harness is designed for a specific engine and transmission combination. They use all new connectors and wires that have the correct color codes for proper wire identification," Dennis explains. "Additionally, all harnesses have a diagnostic connector and a check engine light. In contrast, a factory harness must be cut and spliced for a proper fit. With a Painless Performance harness, everything you need is there, nothing more, nothing less. Likewise, all wires are pre-terminated to tell you exactly where each one goes."
Race Car Wiring
Race cars don't need to power many accessories, but the accessories they do need—such as electric fans and fuel pumps—draw lots of current. To address these needs, Painless Performance offers many different harnesses, relay kits, and switch panels to properly power various high-current devices. "The first decision to make is identifying the end use of vehicle. Is it going to be a street/strip car or an all-out race car? A street/strip car will use a combination of a switch panel and factory switches, while race cars use switch panels only," says Dennis. "We offer both individual panels as well as a complete fuse/relay block assembly. To simplify the wiring process, all the wires, relays, and fuses are designed for carrying the proper current for each device. All the race car harnesses and switch panels we build are NHRA approved. Generally, you can save about 10 pounds by replacing a factory harness with a race harness."
Electric fans are becoming very common in muscle cars, and the good news is that you don't need a fancy EFI system to control them. Painless offers several standalone fan controllers that help simplify the transition from mechanical to electric fans. "We have several different types of controllers that vary in complexity. A simple thermostat can be used to switch the fan relay on and off at a predetermined temperature," says Dennis. "The more complex controllers are computer controlled and use several sensors for inputs. For instance, a thermostat can trigger the controller to switch the fans on and off and to also help control fan speed as required by engine load. They can also control fan operation when the A/C is on, and at highway speeds. Some of our controllers even use multiple inputs like coolant temperature and vehicle speed to determine when and how fast to run the fans."
New cars may be short on character and cool from the factory, but keyless entry and pushbutton start systems are gizmos any car guy wouldn't mind having on their hot rod. Thanks to Painless Performance, it's not just a pipe dream anymore. The company's new Phantom Key brings OE convenience to older cars. "Adding it to any vehicle is as easy as replacing the existing ignition switch with a new pushbutton and installing the Phantom Key control module," Dennis explains. "Once the system detects when the keyfob is inside the car, just press the brakes and hit the start button to fire up the car. The keyfobs can also be used to lock and unlock the doors, open the trunk, or turn on the dome light."
Electronic Transmission Control
Many muscle car enthusiasts with carbureted engines have shied away from electronic overdrive transmissions because they have no way of controlling them. With Painless Performance's new Perfect Torc standalone transmission controller, that's no longer an issue. Available for 4L60E, 4L65E, 4L80E, and 4L85E transmissions, the Perfect Torc system is a fully programmable controller that uses a throttle position sensor and a vehicle speed sensor to create a shift sequence for the transmission. "Using a laptop and the included software, you can create your own high-performance shift points. The system also features a output that connects to an electronic speedometer," says Dennis.
Gauges Made Easy
When transplanting an LS small-block into an older Bow Tie, the factory EFI system already has sensors that monitor vehicle speed, engine rpm, coolant temperature, oil pressure, and oil temperature. As such, it seems silly to add a second set of redundant sensors just so you can hook them up to aftermarket gauges. Painless Performance felt the same way, which is why it developed the new LS Gauge Control module. "The unit plugs into the diagnostic connector, reads input from the various engine sensors, and then sends those signals to the aftermarket gauges through a CAN network using one of several harnesses we offer. This eliminates the need for duplicate sensors and greatly simplifies the wiring process," Dennis explains.