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rev counter unit

Posted: Thu Oct 28, 2010 2:30 pm
by defmonbart
hi
at the moment we are wiring an a15 into a suzuki sj413, we have all the wires sorted except for the rev counter.
in the wiring diagram we have it shows a resistor and a capacitor used for the rev counter. we need to know what values they are ect?

and dose any1 have any for sale??

thanks heaps
Liam

Re: rev counter unit

Posted: Thu Oct 28, 2010 4:17 pm
by Bartman
what rev counter are you using?

Re: rev counter unit

Posted: Thu Oct 28, 2010 4:23 pm
by defmonbart
the 1 from the suzuki

Re: rev counter unit

Posted: Thu Oct 28, 2010 5:10 pm
by Bartman
is not the all the wiring from the car still attached to the engine bay?
There are two ways it can work. Some use a wire from the neg terminal of the coil, and some use a loop. I wouldn't have a clue how suzuki did it sorry.

Re: rev counter unit

Posted: Thu Oct 28, 2010 5:14 pm
by defmonbart
nah we've got no loom from the suzuki or the a15 unfortanitly. would u mind explainiing the 2 ways they were wired? thanks

Re: rev counter unit

Posted: Thu Oct 28, 2010 5:22 pm
by Bartman
Some tachos (well, most aftermarket ones) have four wires;
White, goes to the lights
red, goes to pos on the key
Black goes to earth
and green goes to the neg of the coil.

The other way (Which is also how some datsun are) has a loop wire that goes from (I'm not sure which part of the ignition) to the tacho, and back to where ever it was going. (If you unplug the tacho in a 1200, the car wont run)
The one with the single wire counts the pulses to the coil and works from there. The one with the looped wire must count the pulses differently, but I'm not familair with where that wire comes from/goes to.

Re: rev counter unit

Posted: Thu Oct 28, 2010 6:03 pm
by datsunboy
the loop one just counts pulses too bart....but it picks up those pulses with the inductive loop......exactly the same way the newer timing lights work where you clamp it around a spark plug lead.

I believe the way datsuns have it, is the positive from the IGN goes through the Tacho.....then back down to the dizzy

Re: rev counter unit

Posted: Thu Oct 28, 2010 7:51 pm
by defmonbart
ok ive just spoken to the guy that wired it and he reckons that i actually need the capacitor and resister off a suzuki. as there wired slightly differently to the datsuns, so thanks for your help and ill try get the parts i need off trademe

thanks!

Re: rev counter unit

Posted: Thu Oct 28, 2010 10:17 pm
by fast4motion
Are you sure that the "capacitor and resistor" you're referring to aren't just the condensor and ballast resistor, and have nothing to do with the rev counter?

Re: rev counter unit

Posted: Fri Oct 29, 2010 7:20 am
by sunny79datto
my factory tacho(well dashbord out of a coupe sunny) plugs straight in.. cant member when or why but its stopped working iv got pretronix ignition but its worked since had that in.. so hopefully if you suss yours out i mite be able to get a idea what to do with mine atm iv got wire going to the ballest resistor(little white box) an black wire to the negitive of the coil