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The EZ-Pulse Sending Unit

(Also see the Basic sending unit)
Introduction:

Congratulation on your purchase of the EZ-Pulse sending unit. The EZ-Pulse is designed to mount easily onto any hubcab or wheel cover and provide accurate odometer pulses for your ALFA rally odometer or computer. The EZ-Pulse is constructed from the highest quality aluminum and stainless steel components and with proper care will last a long time.

Mechanical Installation:

Mounting the EZ-Pulse The EZ-Pulse mounts through a single ½ inch hole in the center of your hubcap or wheel cover. Take care to make the mounting hole as close to the center of the wheels rotation as possible to reduce vibration. Use the two 11/2 stainless steel washers provided, one inside the wheel cover, the other outside, to reduce stress on the wheel cover and prevent it's fatiguing. Do not over-tighten the nut which secures the EZ-Pulse or you may weaken the wheel cover or punch a hole into it.

Most "full" wheel covers hold tight enough to prevent the EZ-Pulse from becoming dislodged while driving, however some alloy wheels have only small hub covers which do not hold tightly. In these cases, we have found that a small length of strapping material or baling wire used to secure the wheel cover to the wheel will solve this problem.

Secure the cable leading from the EZ-Pulse so that it does not contact the tire. Make sure to leave enough slack in the cable to allow the car's suspension to travel fully in both directions without stressing the cable.


Front wheel drive installations: EZ-Pulse on front wheel

Mount the EZ-Pulse on the rear left wheel for maximum accuracy. (Magnetic trees and Rock-a-dillos are statistically more likely to attack the right side of the car than the left.) Route the cable horizontally so that it enters the car at either the hatchback (trunk) or through a door. Use a nylon cable tie to secure the cable to a fender or some other stable part of the car for extra support. There is usually a screw or drain hole pre-existing in the wheel well which may be used for this purpose.

Rear wheel drive installations:

EZ-Pulse on rear wheel The EZ-Pulse should usually be installed on the front left wheel. Because the front wheels must pivot to steer the car as well as travel vertically with the suspension, extra care is require when routing the cable. The cable should be attached to the fender directly above the center of the wheel. You may do this using either a cable tie or strapping material attached to an existing hole in the wheel well, or running under the hood to the top of the shock tower. Make sure you leave enough slack in the cable to allow the wheel its full range of motion, but not so much that it flaps around. Test the installation by turning the steering wheel from full left to full right and examine the clearance between the cable and the tire.

Electrical Installation:

Route the cable from the EZ-Pulse to the computer using as short a run as possible. Make sure that you do not route the cable past your cars ignition coil or spark plug wires if the cable must run under the hood as this may cause interference with normal odometer operation.

The EZ-Pulse provides a standard three wire interface (power, ground and pulse) to your odometer. The RED wire is the power wire. The EZ-Pulse will operate properly with voltages ranging from 5 volts through 20 volts. The BLACK wire is the ground. For best results, the EZ-Pulse should be grounded at the odometer's ground connection - not through the chassis of the car. The GREEN wire is the pulse connection.


EZ-Pulse mounted on Miata front wheel
Notes:

1: After each rally, the EZ-Pulse should be removed from the car and inspected. Clean dirt and grit from around the external moving parts with a light stream of plain water. (Do not use detergent to clean around the bearing as its lubricant may be washed away!) Allow the unit to dry thoroughly before storing it. The inside of the EZ-Pulse is sealed and should not require maintenance.

2: Never attempt to disassemble the EZ-Pulse. Removing or loosening the inner shaft nut will lead to failure of the EZ-Pulse.

3: The EZ-Pulse provides two pulses for each revolution of the wheel. In some rare cases, more pulses may be required to obtain a usable odometer factor. If this becomes necessary, contact the factory to have your EZ-Pulse modified to provide 3 pulses per revolution.

4: If you are using the EZ-Pulse with a Chronar odometer you may need to attach a resistor between the GREEN and RED wires. A 4.7k ohm, 1/4 watt resistor, available from Radio Shack, should do the job.

5: The EZ-Pulse should be compatible with most brands of electronic odometers. We have not tested it with makes or models other than ALFA, and make no claim as to the suitability of the EZ-Pulse for those applications.


Plain English Warranty:

The EZ-Pulse is warranted for a period of one year from the date of original purchase. The warranty covers defects in material and workmanship only, and not failure due to mechanical overstress, abuse, or normal wear. In covered cases, the EZ-Pulse may be repaired or replaced at our discretion. While every precaution has been taken to produce a quality product which should last for many rallies, we take no responsibility for losses due in whole or in part to the malfunction of this product.

ALFA Rally products are built in the USA by the rallyists at:

Small Systems Specialists
201 N. Lobb Ave.
Pen Argyl, PA 18072
Phone 609-301-0541, Fax No Longer Available!
Email to: ALFA@Rally.cc

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