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Tach not working correct

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sjgcpa

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I recently bought a 66 BJ8. One of the things I did not originally notice was the Tach is not working correctly. It only moves in a range of about 15 to 25. Any idea how to fix it? Do you think it is the gauge or the cable?

Thanks
 
Hi Scott,
Does your tack have a cable? I’m not sure exactly when the switch was made to electric pulse, but I would have thought it was before ’66. /ubbthreads/images/graemlins/confused.gif
 
HI Sjgcpa, Look on the back of the Tach and you wil see a white wire loop captured in a small fitting,make sure the little clamp is tight.Also make sure the grounding wires and their thumb screws are also inplace and tight.Check the connectors at the coil and insure they are clean and tight also.Should you have an electronic ignition there are other issues.--Fwiw--Keoke
 
If you have an electronic ignition (Pertronix), just accept the fact that the tach probably won't be accurate. If you do not have an electronic ignition, it is possible that one or more capacitors inside the tach has malfunctioned. They can be replaced fairly easy. Use the search feature to find related threads. Also two companies, Nosingers and MoMa Manufacturing rebuilds tachs.
 
sjgcpa,part numbers for mechanicl (cable driven) tachs,seem to end on the 1963 bj7,so id guess yours is electronic .or at least should be.
 
If it goes to zero when the car is off but is just reading high like 1500-2000 when the car is at an idle, probably one of the capacitors is bad. You can buy a suitable replacement at radio shack and replace it and then recalibrate it. If it's a hopeless case and the movement is also sticking, read the article that our own Doug Lawson wrote about how to replace the " inards " with those of a donor tach. https://www.britishcarforum.com/lore/article.php?id=063
 
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