6 replies to this topic

[jaffercake]

hi, i am confused about how to wire my rev counter. its a Yazaki rev counter shown in the pictures. it has 5 wires, 2 red ones, one blue one, one yellow one. and one black one. i know that one of the red ones is for the bulb and the other red one is earth (just for the bulb?). i have tried every combo i can by putting wires on the coil, one on + and one on - but nothing is happening. will it have to be wired in series or something?? somebody help pleasseee. pictures below. thanksss jaffer.

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[datsun100a]

try
blue neg side coil
yell pos side coil
blk ground

not sure about the 2 reds

saabs use or did use yazaki tachos

[dklawson]

See the picture in this older thread.

http://www.theminifo...p;hl=tachometer

[jaffercake]

i used the picture and it worked but only just. the needle only travels a veryy small amount, it goes to about 500rpm no matter how hard i rev it. so i tried different settings, like changing it to work with a 6 cylinder engine and when i switch the engine on it goes to just under 1000rpm and thats without even earthing it, when earthd the needle goes all the way to 8000rpm. th reason for not earthing straigh away is because i was doing it on my own and had to hold the wire in place after turning the engine on. so anyway, i set it back to 4 cylinder and it still only moves a tiny little bit. does this mean that its nackered for the 4 cylinder setting? im going scrap yard tomorow so i will see if there are any good ones and check if they work on my engineee, if not then ill pick one up from stanford hall on sunday

its a shame because i realy like the look of this Yakazi one

can it be repaired (if broken) and where?

cheers jaffer.

[bigmotherwhale]

sounds like its working ok, you might have just wired it wrong? the reds are probably positives one for the light one for the power to the rev needle electrics, if you wire it wrong tho it will damage the circuit inside

[dklawson]

I'm at a loss to suggest anything constructive as I don't know Yazaki tachometers.

However, none of your early tests will be meaningful with the ground wire disconnected. As a start, I would go back (WITH the black wire earthed ) and make sure that the yellow and blue wires are on the correct low tension terminals. That is to say, the blue wire would be on the coil terminal with the white/black wire going off to the distributor. The yellow wire would be going to the coil (+) terminal which should have a white wire on it coming from the ignition switch.

If your coil (+) terminal has a pink and a white/yellow wire on it, this indicates a ballast ignition system. If that's what you've got, you will need to move the Yazaki yellow wire to a different point. You will need to supply the gauge with a full +12V.

If you really like the gauge and there are no external wiring errors I'm sure you could find a shop willing to fix this. However, it is an old piece of electronics and may cost more to fix than it is worth.

[jaffercake]

i tried the tests with and withought the earth connected but it stil doesnt go over 500 rpm on the gauge and only moves slightly. i think im just going to go for a smiths one as i have seen some really nice ones on ebay
thanks for all the replies anyway, much appreciated.
jaffer.