Tacho booster/adapater?

[mrbigport]

Hey, just recently got a silvertop dropped into my sprinter and the tacho is reading wrong. I put in an 3" or so autoguage tach. The tacho worked ok before the conversion

Anyways, would i need a tacho booster, or would i just take the signal from the ecu? Im not really 100% sure what to do because the other topics are mainly about ca18's and gze's

Any help would be appreciated

THanks

[mattysshop]

what sorta ignition system are you using??

[mrbigport]

Just running the stock dizzy and stock ecu for the silvertop.

If i did need a booster, would this be suitable to make my own?

http://www.toymods.net/forums/showthread.php?t=14404

[mrbigport]

Guess i already have a tacho booster in the car, the wiring guy already installed it.. So maybe the problem is that i have one, rather than i dont.

Anyways, how would i go about tapping into the IGN -ve from the coil? do i just tap the line near the coil and run a wire through to the dash? or do i just find where the wire goes somehow and tap it closer to the dash?

Also, would any of you know what the yellow wire on Autogauge Tacho's be for? I get illumination as soon as i turn on the ignition regardless if my lights are on or not.

Cheers

[Hyuga]

Don't know whats the booster is for but on the other thread they say its for new mottor with old tacho, but you hav a rather new motor and new tacho now so whats the point to hav one?

Anyway your tacho has 4 wires, they are tacho signal(green), negative ground(black), ignition(red), light(orange). There shouldn't be illumination without your parker/headlights on. I think you hooked up the light wire to ignition as well so it illuminates all the time.

[mrbigport]

Booster converts 12v wave into 5 square wave or something? Anyways, the problem is fixed now. Me and drif86s worked our way around it. We tapped into the negative ignition coil and sent the new wire to the tacho and the tacho works fine. I spose the booster was messing around with it.

And i definitely have not hooked up the red wire to the illumination, i have triple checked all the wires. Red- ignition, black- ground, green- negative ignition coil and yellow- illumination..

Maybe thats why i got the tacho for so cheap? anyways never mind, its a small imperfection.
Maybe, ill try tapping into the headlight and sending that wire back to the dash..

Thanks for the help ya'll