Tach Trama

[Anonymous]

I have a 83 GS 750 ES, I do believe it is the first bike with and electronic tach. I have checked the other form out on the electronic tach on the site but mine is not the same. Mine works on DC voltage, 1VDC = 5500 RPM and 2.2VDC = 12000 RPM. Now here is my problem, when I bought the bike the guages were a mess :? . The tach has 2 wires coming out of the back a red one and a black one, what I need to know is where the heck do these wires connect as they were cut when I got the bike.

Any help would be apriciated

Mark

[jtcrespo]

Sounds like you have an aftermarket tach, or at least the tach off of another bike.

My memory and my manual both say that the stock tach connects with three wires. If you have the original harness, the colors are orange, black/white, and black/yellow. Orange may be orange/green coming out of the harness.

The black/yellow goes into the ignitor box.

The b/w seems to be connected to most of the lights, reg/rect., battery, and fuse box.

Orange goes into several switches including the ignition switch

That's all I know! As far as what you need to connect to, hopefully someone else can help you.

Please test with a multimeter first.

[Anonymous]

voltage

I don't know if the tach will work but i don't think they work off voltage as such, they work off pulses. The reason you're seeing the voltage difference is there's more pulses at a higher rpm (obviously) which would show a higher voltage. The multimeter doesn't have time to drop back down to 0V.
Same as your house power, if you read the peak to peak voltage on 60 cycle power the max voltage is 170 or somewhere near that not the 110 that you read on a multimeter (true RMS voltage).
If I had to take a guess (and it's only a guess) I'd say the red goes to +12 the black goes to the coil that receives the pulse from the ignitor. But I think, as was already stated, there should be 3 wires, one for +12V, one for -12V and one for the signal.
Just my measly 2 cents worth.....Mike

[Anonymous]

I do believe they are the original gauges, and I know that they run off of a DC voltage. I had them tested at work and the gauge test fine, so I know the gauge is not bonk. The reason I say they are the original gauges is because the tach is in the original housing and it is imposible to replace it in the same housing. I alos looked at the manual but that manual is for an 84 onward gs and mine is a year older. I asked at the dealership and the gauge cluster for an 84 is different than that for an 83.

Thank in advance
Mark