bling tacho not reading right.

[SiKiD_01]

i have a fancy bling tacho gauge my mate wants to give me.

problem is, i hooked it up to give it a test, and its not reading right, and on top, it doesn't have a calibration or zero button.

i hooked it up as it said, 4 wires, battery (+) and (-), ignition 'ON', and last one said to connect to ignition. done.

(oh yeah, it has several different colours for the back light)

question is, is there anything i haven't done, or is there anything i can do to set it correct? it reads half of what it should read, eg: reads 1500 at 3000.

it has a 4,6, and 8 switch, but 6 and 8 read real slow and lower. (i assume it should be like this)

OR

should i just decline, and wait for other free stuff???

thanks.

[OldGold]

What about it doesn't read right?

[roc box]

a lot of tachos fire off the neg side of the coil that might be it

[SiKiD_01]

i had it connected to the neg side, pos side didn't work at all.

oh well, might just have to forget about it.

thanks

[Santos]

did you have your factory tacho hooked up at the same time... cause if you where trying to drive two tacho's from the same source you would be dividing the signal into two

Now as the factory tacho probably doesn't need that much power it would stay near accurate but the universal bling tacho has to have a much higher resistance so in turn would require much needed power (on account that it has to cope with a broad range of conditions)

that's all i got on the secret consipiracy theories

[muppet_man67]

I dont know anything about these things but I would ask if the alternator output would affect something like this. A sierra alternator would put out less power the say a vn commo that its probbaly mainly used in.