Slide behind the wheel of any contemporary car and more than likely you’ll be faced with an instrument panel full of warning lights to indicate what catastrophe has already happened, or a great big gas gauge and an assortment of dials that seem to always be in the middle of the scale no matter what. Most modern cars supply the driver with more information about the climate control system and stereo than the engine.
Auto Meter’s full sweep electric...
Auto Meter’s full sweep electric gauges incorporate the latest high-tech internals that provide full sweep indicators and unmatched accuracy. Note the LEDs used for illumination.
To keep tabs on the operation of our blown Chrysler-powered Gasser, we wanted to have all the pertinent read-outs readily available. To do that we chose gauges from Auto Meter. One of the best-known names in the industry, Auto Meter has been in business for over 50 years, producing quality instruments that are second to none. They offer an unmatched variety of designs and styles, and if you’re looking for something that is one of a kind, Auto Meter’s Custom Shop can provide that as well.
For the race car vibe we were after we stopped looking at Auto Meter’s options online when we found the Ultra-Lite II line of gauges. They have a no-nonsense look with a silver face, black numbers, and red pointers—at night the colors reverse, and as a result of “through the dial” LED lighting, the faces turn black with white numbers with glowing red pointers.
Mechanical gauges, like this...
Mechanical gauges, like this 0- to 100-psi Auto Meter oil pressure gauge, have full sweep face, which makes them easy to read.
Our Plymouth’s original dashboard was modified by covering all the original openings with sheetmetal. The new flat panel was then punched to place the speedometer, temperature, and oil pressure gauges positioned directly in front of the driver. The other instruments: vacuum/boost, volts, fuel level, fuel pressure, and an air/fuel ratio mounted to the right. Of course the tachometer is mounted in the classic spot up top.
While instruments are often chosen on the basis of their appearance, there are a number of differences in the way they operate as well.
This is a 0- to 100-psi short...
This is a 0- to 100-psi short sweep electric oil pressure gauge. It’s critical that the correct senders are used with electric instruments.
The operation of mechanical gauges hasn’t changed much over the years. Inside there is what’s called a bourdon tube—patented in France in 1849 by Eugene Bourdon, it’s a flattened tube shaped like a C. Pressure, which may be oil from the engine, ether in a bulb, and tubing in the case of a temperature gauge, causes the tube to straighten slightly (vacuum gauges work in a similar way). The tip of the tube is hooked to a link and gears that are calibrated to move the needle to provide a reading.
Auto Meter’s mechanical gauges use a bronze bourdon tube for precisely calibrated 270-degree sweep movements. These mechanical gauges require no electrical power for operation, making them an ideal choice for vehicles with no- or low-powered electrical systems.
Here is an Auto Meter short...
Here is an Auto Meter short sweep temperature gauge. Note the sender (arrow) has a single connection.
Designed for durability, Auto Meter’s liquid filled mechanical gauges use 270-degree sweep Pro-Comp mechanical gauge movements filled with a liquid silicone compound for extreme vibration dampening and smooth pointer movement. These gauges are proven to give steady and accurate readings in the harshest of competition environments, including NHRA Top Fuel Funny Car, Baja 1000, Off-Shore Marine, and on the Bonneville Salt Flats.
Full sweep electric instruments,...
Full sweep electric instruments, such as this temperature gauge, use a microprocessor to control the stepper motors that mount the indicator needle. Senders for these gauges can be identified by their two electrical leads.
Short Sweep Electric
Auto Meter’s Kris Carlson describes these gauges as calibrated ohmmeters. There are two components to an electric instrument: the gauge and the sender. Housed in the gauge is an indicator needle that is attached to an armature that turns inside coils of wire. When current is supplied to the instrument it flows through a series of windings and then to what’s called a sender (it may be pressure, temperature, or fuel level) that is grounded. As the current flows through the windings it creates a magnetic field that causes the armature to turn (which moves the needle). How far the needle moves is dependent on current flow through the coils, which is controlled by the sender.
Electric gauges have a number of advantages. The sending units keep hazardous fluids out of the passenger compartment. As electric gauges and senders are calibrated to work together they must be matched.
Some early OEM electric gauges...
Some early OEM electric gauges used a thermal element; as the current flow is varied by the sender, the element changes temperature and the needle moves accordingly. Accuracy is poor, but these gauges are cheap to produce.
This is a mechanical gauge...
This is a mechanical gauge that uses a bourdon tube. As pressure (or vacuum) acts on the tube the end deflects and moves the needle on the gauge face.
Modern full-sweep electric...
Modern full-sweep electric gauges resist vibration and provide steady readings. In addition, accuracy is in the 0.5 to 1.5 percent range; better than any other design.