how can i get my rev counter to stop giving me half readings?

i think its sumit to do with my car being a twin coil, i would switch the rev counter to 2 cylinder, but its only goes as low at 4 the one i got, and the 2 cylinder ones are expensive

cheers guys

 

This will sort your problem.

Altho there is no need for the zenner diode or the resisters after it.

If that doesn't work then use a 1k ohm resister after the diodes from a 12v supply to pull up the voltage while retaining the signal (if that makes sence)

 

apreciate the quick the reply... so, where do i get the diodes form etc??

 

Maplin - couple of quid for them.

To be honest, I would be tempted to use 1N4004 instead of 1N1001 as they are a bit beefier and handle a bit more current

 

1001 ...where bouts is that?

so,

i get each wire, put the 4004 diode in each then join then, then put them into the tacho?

 

Thats right dude

 

cheers fella! will try and get the two diodes 2mz!!! so theres no need for the 15v 'zender'

THANKS mate!!!

 

1N5408 work much better, and are MUCH beefier.
tabetha

 

Overkill.

1N4004 is far more suitable and readily available for pennies.

 

No need for the zenner neither - its only there to protect the diodes from any back-emf from the tacho - and tbh, the 1N4004 diodes are more than capable of withstanding that and any reverse current

 

brilliant, gna try and get down maplin 2mz morning!

so i get the 2 wires, out the diodes inline, join the wire then attach to the tacho wire?

( sorry for all the questions, wiring om ok with, but this has had me stumped!)

 

and its 1n4004 ye not 1n4004s?

cant seem to find one eithout a number after it? any1 got a link to the maplin site with this diode on it?

 

any1? jus want conformation cos im getting these 2mz!