Tacho needle bounce 1971 beetle

jakeandco1958 Commited Dubber

51 posts · joined Aug 2012 · 16 Aug 2015, 8:49 am

#1017815

I've just fitted a Saas 52mm Tacho which works but needle bounces all over the place. Have tried the following. Made sure it was connected to negative side of coil, fitted a resistor between coil and gauge, checked and changed earth wire, setting on rear is set right. 4 6 8 Other suggestion is fitting a diode. Any ideas?

shokwave2 Officially Full-On Dubber

289 posts · joined Mar 2010 · 16 Aug 2015, 4:06 pm

#1017828

You'll need to install a diode between coil and gauge. I had the same problem.
http://www.thesamba.com/vw/forum/viewtopic.php?t=566900&highlight=diode

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 16 Aug 2015, 11:40 pm

#1017864

Yea the diode is needed to allow residual current freewheel to earth 🙂

madness is in the eye of the beholder 👍

jakeandco1958 Commited Dubber

51 posts · joined Aug 2012 · 17 Aug 2015, 12:44 pm

#1017877

thanks. worked a treat. soldered a diode in and now tach works well. cheers