Here is a simple
schematic of the circuit. Note the center leg and the tab are both common and used for grounding. I opted to use the
tab as ground and cut the center leg off. I felt that the ground being so close to the 12 volt in and the 5 volt out could
be a problem.
The old IVR was gutted and the case was used as a heat
sink for the voltage regulator. A small hole was drilled in the bottom to mount
the regulator. Note the 12 volt INPUT is on the left and the 5volt OUTPUT is on the right
20 gauge wire is soldered to each leg. Be careful to not
to get the legs to hot with the soldering iron. Use a small pair of needle nose as a heat sink on the leg near the body of
Heat shrink tubing is applied to each leg to insulate and strengthen them. The legs will break if you bend them to much!
I found if you shape then and then use a heat gun they will stiffen considerably with the tubing and hold there
Heat sink grease is applied to the back side of the regulator (a little goes a long ways) and it is screwed into
the case. The heat sink grease can also be purchased at Radio Shack.
The wires are looped around and another small hole was drilled in the side. A zip tie was installed as a stress
relieve for the wires to keep them from moving.
Another view with the Zip Tie cut off
10.0µF 50V Axial-Lead Non-Polarized Capacitors are soldered to each
lead. The other end of the capacitors is soldered together and will be connected to the case which is ground. Heat shrink
tube is applied to all solder connections.
Connectors are applied to the ends of the wires. The 12 volt wire has the male spade connector and the 5 volt wire
has a female connector.
More shrink tubing
over the capacitors and a zip tie to hold the ground lead in place. Note the male and female spade connectors.
The ground ring connector will mount to the screw
that holds the IVR in place on the instrument gauge.