Hooking up a tachometer on a 1982 S-10 is not complicated. The 1982 S-10 uses a distributor housing an ignition control module and crankshaft sensor with a remote coil. The crank sensor determines the location of top dead center on the No.1 cylinder and the speed of the engine. The ignition control module increases the timing with the rpm and supplies the ground for firing the coil.
Instructions
- 1
Take the tachometer out of the box and look it over. Read the instructions for setting the mode to the proper selection for the number of cylinders. Depending on the manufacturer, there will be an access hole in the rear of the tachometer behind which is a switch with "4-6-8 cylinders." If no switch is present, there will be three wires of different colors. One of these wires must be cut to select the mode. Do this now.
2Notice that there are four wires on the tachometer --- a red battery wire, a black ground wire, a yellow illumination wire and a green tachometer coil connection wire. Find a good location for the tachometer, easy to see without taking your eyes off the road and clear of any obstructions.
3Install the tachometer as per instructions, with the supplied parts. Connect the red positive or battery wire. It must be installed on a wire that has power only when the ignition key is in the "On" position. This wire will be spliced into the accessory wire from the ignition switch located on the top of the lower part of the steering column.
4Connect the voltmeter black lead to any good ground. Use the red lead to probe the wires coming out of the switch on the right side. With the ignition switch on, probe the wire terminals to look for power. Once you find power, turn the ignition key off and once again look for power on the same wire. Continue probing until you find a wire that has power when the key is on and no power when the key is off. This will be the accessory wire.
5Conceal the red and yellow wires as much as possible while passing them through the dash down to the ignition switch. Cut the red wire to length at the ignition switch. Install the quick connector over the ignition switch wire and insert the red tachometer wire into the connector as well. Compress the metal blade down to pierce the wires, using the pliers. Fold the plastic cap on the connector over the top of the metal blade and wrap some electrical tape over it to keep the top snapped down.
6Connect the yellow illumination wire on the same wire in the same manner with another quick connect. This way the tachometer will be illuminated while the engine is running and off with the key. This is the most common wire connection however, if it is desirable to have the tachometer light come on with the headlights only, access the headlight switch and probe for a power wire that's hot with the switch on and off when the switch is off. Attach the yellow wire to this wire with a quick connect. As a note, tachometers are hard to see with the light off, even in daylight.
7Connect the black wire to a good ground on a metal part of the dash or frame. Look for a bolt such as the ones on the side of the dash that hold the dash in place. Place a metal ring connector on the end of the wire and crimp it in place. Clean any paint off from under the bolt. Install the wire and tighten the bolt.
8Run the green wire down and through a grommet in the firewall, preferably the grommet behind the fuse panel. Bring the wire across the top of the cowl panel wire and tie it to the harness. Cut the slack out of the wire at the ignition coil. Attach the green wire to the negative terminal wire on the coil using a quick-connect as before. The negative terminal wire will have a (-) under the terminal and it will also lead to the distributor. Place some electrical tape around the quick connect.
