how many

[Fuelie600]

How many guys have operated more than 1 component off the factory tach lead by the alternator? IE. tach, shift light, pump controller, ect. I currently am running a pump controller, and am wanting to install a tach. Don't know if this will be too much demand from that signal. Thanks, Brian

 

[Fuelie600]

Ttt

 

[salvageV6]

In theory they should be a high impedance very light load to the tach. line.

Manufacturers specs. is the only way to tell for sure.

I've never seen them posted for the tach. signal (drive ability) or the load impedance for those type devices, so trying them is probably the only way to tell.

I wouldn't hesitate to put a tach. and a pump driver on at the same time for testing.

An automotive or electronics oscilloscope at idle on the circuit would tell you if there's any load on the signal as the devices were hooked up.

.

 

[Fuelie600]

I'll have to hook up the tach and see, as you mentioned. I do know that my shift light would not work off the tach lead, so my thoughts are that 2 components would be too much also. I was kinda hoping that some guys on this board have multiple devices ( or tried multiple devices ) and could chime in with their experiences. Brian

 

[Fuelie600]

Well, I just hooked up the Autometer tach on the same signal wire as the Aeromotive fuel pump controller. Apparently, they will not work together off the same signal wire. Any thoughts Salvage?