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Tacho Blues-day

We recently removed a well-worn CompuFire distributor from our Volkswagen Bay Window Type 2 and fitted a "like new" VW factory distributor - back to the stock configuration. However, after doing so, our VDO tach now read approximately 1500 rpms too high and the needle bounced all over the place while driving.

Upon investigation on TheSamba, we discovered the tach needed a supplement, inline diode to stop "ghost" signals interfering with the signal to the tach. The needed diode was a #1N4005 type with the silver marked end going toward the tach.

We created the diode fix as shown, installed it on the VW Bus, and the tach is now back to normal; no bouncing , no inflated readings, and no wild swings. RPMs are steady and correct.



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