Notes For Analog Circuit Board Models

Note well: This page is not intended to replace the Analog EFIE Installation Instructions. It is merely trying to give you the differences between the circuit board models and the Deluxe Analog Series models. After reading this document, go back to the Analog EFIE Installation Instructions and follow them to install your circuit board.

The circuit board series and the Basic series are the same. The Basic series units have just been dipped in a protective, insulating material. These models are installed the same way (electrically) as the deluxe models. The directions that tell wire colors and what they connect to, are the same for the circuit board models.

Rather than using the switch on the Deluxe model, you will have to switch power to the red wire yourself. Another thing you'll want to address is a way to easily make connections to the white and green wires for making adjustments to the EFIE. In the Deluxe model, the white wire connects to the red test port, and the green wire connects to the black test port. Instructions that ask you to make measurements to these ports, either here, in other documents on this site, or on the support forum can be done by connecting to the white and green wires from your circuit board. For Dual units, on the 2nd EFIE, the blue wire connects to the 2nd red test port and the brown wire connects to the 2nd black one.

The pictures below show the EFIE circuit boards. Note that the photo of the Dual circuit board shows the parts for both EFIEs on the board, designated by the numbers 1 and 2. The final picture below shows the newest version of our Single EFIE that you will start seeing more of. It's the same design as the previous board, but uses surface mount parts which allows the board to be smaller.

Voltage Adjustment Potentiometer

The voltage adjustment potentiometer is the main adjustment for the EFIE. This is where the user adjusts the EFIE for his particular vehicle and fuel saving device(s). On the Deluxe series models this adjustment is mounted on the enclosure, so the circuit board will not have an R6 or R6A potentiometer on the circuit board.

Range Adjustment Potentiometer

This is function has been discontinued. If you wish to find out more about it, please see "How To Adjust The Range Of The EFIE". I recommend that this pot never be touched except by advanced users.

Dual EFIE Circuit Board

Single EFIE Circuit Board

R6: Voltage Adjustment - EFIE #1
R6A: Voltage Adjustment - EFIE #2
R4: Range Adjust - EFIE #1
R4A: Range Adjust - EFIE #2
J1/J2: Heater Jumpers

Note that the wire colors for the Dual EFIE circuit boards are the same as for the Deluxe model. White/Green are used for EFIE #1, and Brown/Blue are used for EFIE #2.

I'm sometimes asked about what wire size you should use to extend the EFIE's wires. Well, any wire will do. The power drawn by a an EFIE is minimal. We usually use 24 or 22 gauge wire which is more than enough copper to handle the minimal currents involved. I also prefer stranded wire, because it is less likely to being damaged by moving it around. But that's a preference. Solid or stranded wire will both work fine electrically.

Single EFIE Circuit Board

Single EFIE Circuit Board

Heater Jumpers

We have found that extremely cold weather can adversely affect the functioning of an EFIE making it take longer to arrive at it's set point. Folks that live in a climate where it is below freezing a significant number of days per year are advised to set these jumpers. J1 will provide moderate heating, J2 will provide about double the amount of J1, and setting both jumpers will provide the maximum amount of heat. Use both jumpers in New England for instance where it is too cold for human habitation from November to March each year. If you change the jumper settings, note your voltage setting before hand, and then you'll probably need to re-adjust the voltage slightly after the change.

Test Points

The Deluxe series EFIEs have test points built in that you can plug your volt meter leads into for the purpose of setting the EFIE. Other tests can be done with these test points as covered in How to Read Your EFIE. You will need to provide access to these test points yourself so you can set your EFIE and do these other tests. On the Single EFIE circuit board models, the white wire connects to the red test point, and the green wire connects to the black test point. For Dual models you also have a blue (or another white) that connects to the red test point for EFIE #2, and a brown (or another green) that connects to the black test point of EFIE #2. By giving yourself access to these wires, you will be able to follow any instructions given for the test points in the Deluxe series, by connecting your meter leads to these equivalent wires. Note: be sure these wires aren't allowed to contact other wires or ground, or the EFIE and your oxygen sensor will not work until the condition is corrected.


With the information on this page under your belt, you can now go to the EFIE Installation Instructions and you will know how to apply them to your circuit board.

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