They are available through several aftermarket manufacturers. How to fix a bouncy tach needle.
Autometer Sport Comp Playback Tachometers 3966
Autometer tach not working. Examples of these items are 5312 5313 and 5314 as well as the recently discontinued 5310. Check that the back of the tachometer has a switch set to 12 standard on all 12 volt tachometers matching the boats 12 pole system. In this case you are not dealing with a weak signal but rather a dead signal or no signal. What if the pull up resistor trick did not work. If you dont find it there get the appropriate haynes manual for your car. Some ignition systems are electronically noisier than others.
In this case you may use an autometer tachometer adapter. 70 chevelle ss clone 632 ci powered. The adapter will not use anything from the computer or the original tachometer signal wire. Calibrate your autometer tachometer to your engine size as follows. For this reason your oem tach that was circuited to read the latter does not recognize and cannot read the signal its receiving from the newer style distributor. Check your boat wiring manual to confirm your voltage if your not sure what it is.
Repeat this on the other side of the engine as well. The fix for this situation is to purchase a tach filter or interface device. The tachometer adapter will wire in series between both banks of coils and their power supply. For a six cylinder engine clip just the brown wire and for an eight cylinder engine do not clip either of the wires. You just need to hook it directly to the box like the diagram shows. Turn the tachometer over gently so that the backside is exposed.
A classic symptom of a loose wire connection is erratic display of readings. Run the power side pinks left right together and attach to the solid red of the adapter. Sometimes corroded wire connections and breakage may be the reason for the tachometer not working. He might but according to the chart shown on that msd webpage that i linked to the autometer tachs dont need the tach adapter. Tach adapter 2650 561x 10 revc. Check the tachometer wiring section in the car manual.
Pink power wire away from the coils connector to where it is most comfortable to work with auto meter suggests 2 6 away then cut this wire in half. Yepyou need a tach adapter. If you have a four cylinder engine clip the two looped wires on the back of the tachometer with wire cutters. If you are using a factory tachometer or an aftermarket tachometer that does not have shift light controls you may still use any of the above mentioned shift lights but you will now need an rpm switch an rpm activated module or playback box. Follow along with the autometer crew as we remedy this problem. Nothing besides the steps we took in the video were done.
While proper grounding of the tach and routing of the signal wire go a long way towards preventing this sometimes its not enough.
Gallery of Autometer Tach Not Working
