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Hairball tach input

965 Views 1 Reply 1 Participant Last post by  3L3CTRIC
My 10 year old Zilla based conversion is having a problem. The tach has been working for years, but recently the needle started to stick, then the Zilla starts to cut out. I figured out it was the Stall Detect and turned it off. That allowed me to continue to drive it, but not long after, the tach stopped working entirely. I replaced the sending unit, which did nothing. I can see the pulses on my meter on the Hairball’s signal input and the tach works when I option the Zilla to show amps. This all leads me to believe the hairball tach input has died.

Could it be a simple loose wire or bad solder joint or am I in for replacing the hairball?

Thanks for any help.
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Discussion Starter · #2 ·
Well I opened up the hairball. Didn’t find any cold solder joints or any obvious issues with it. There was continuity in the circuit and the resistors on the Tach circuit measured the correct resistance. Not much else I can do.

Here’s a shot of the inside of the hairball for those of you who are interested:


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