tach wiring question
 

Autometer Ultimate II tach, does the blue wire see 12 volts constant and to activate record feature you use a momentary OFF switch or does the wire see no power until a momentary ON switch is activated. The instruction booklet and tag on wire contradict one another.

Re: tach wiring question
 

When the tach goes from 12 volts to 0 volts it will start recording. I have it wired to the line lock button but have a separate "arm" switch in the circuit that I activate after the burn out to allow the blue wire to see the 12 volt signal from the line lock circuit on the starting line. When I let go of the line lock button and the voltage drops to zero the tach starts recording.

Chad

Re: tach wiring question
 

I just installed one of these also, and have been fighting with it... I have the 12 volt running to it, with a normally closed button by tach. I push it, dropping the 12 volts as I stage. Should start recording - correct? The 12 volts do go back to it immediately (momentary break of voltage).

I am not getting recordings, and the shift light does not function correctly when it does not record.

Does the voltage have to drop for any certain amount of time?

What else could I be doing wrong? (loaded question I know... lol)

thanks,

Ken

Re: tach wiring question
 

Ken ~ Sounds like you got it hooked up backwards. Should be: when you push the button (ie transbreak, line lock, etc.) is when the power should be running to the "blue wire". When you let go of said button, the power should drop, starting the recording function. Again, no power to the blue wire until your button is pushed. Button release, power drops off and recording begins. Hope this helps ya out.

Re: tach wiring question
 

I haven't wired one of those in several years, but if memory serves me correctly you have it backwards. I think there should be no voltage on that wire and by applying 12 volts and then taking that voltage away the tach starts recording.
Chuck

Re: tach wiring question
 

Thanks for the feed back guys; the correct wiring IS no power to the blue wire unti the momentary switch is activated giving it 12 volts and removing voltage when the switch is released. really apprediate your help! thank you.

Re: tach wiring question
 

Then its usually arrow key down. Enter, Enter should say pre. Should work.

Re: tach wiring question
 

I second the thanks everyone!
At least it should be an easy fix.

Ken

Re: tach wiring question
 

Remember not to wire it to the trans brake. Tech gets very upset when more than one wire is hooked up to trans brake.