Precision Speed Instruments, Inc

CONVERSION FROM MECHANICAL

Solutions ...not problems

Efficient Way	Costly Way

1	Replace cable assembly with PSI wire harness. Connect red wire to keyed power, black to battery ground, and blue to dash lights. The 2 conductor wire connects to the sender-generator.
2	Install sender-generator on the transmission speedometer drive. (A magnetic sensor may also be used with rotating metal pieces.)
3	Divide the number on the ratio adapter into 1000. (i.e. 1000 ÷ 1.0263 = 974.37). Now calculate Full Scale hertz by: (974.37 x 2 x 80) / 3600 = 43.31 hz
4	Find switch numbers that are the closest to 43.31. Since 43.46 is the nearest, push down on switches 1, 2, 3, 7 & 9. (pictured below).	Freq. Switch Closures Freq. Switch Closures 39.34 1,2,3,6,7,8,9 43.46 1,2,3,7,9 39.73 1,2,3,6,7,8 43.89 1,2,3,7 40.13 1,2,3,6,7,9 44.33 1,2,3,8,10 40.53 1,2,3,6,7 44.77 1,2,3,9,10 40.94 1,2,3,6,8,9 45.22 1,2,3,10 41.35 1,2,3,6,8 45.67 1,2,4,5,6,7,8,9,10 41.76 1,2,3,6,9 46.13 1,2,4,5,6,7,8 42.18 1,2,3,6 46.59 1,2,4,5,6,7,9 42.60 1,2,3,7,8,9 47.06 1,2,4,5,6,7 43.03 1,2,3,7,8
5	Set odometer and install head.
Note If inaccuracy is thought to exist, multiply the Fs hertz setting by the odometer reading "over" a known distance driven. i.e. (10. 8) / 10 x (43.31) / 1 = 46.77 which is the new setting (close switches 1, 2, 4, 5, 6, 7 & 9)
OR
i.e. (10.1) / 11 x (43.31) / 1 = 39.77 which is the new setting (close switches 1, 2, 3, 6, 7 & 8)