I have a 1994 3500 with a 350 TBI. It doesn't have a tachometer. I would like to instal one. My auto mechanic said I shouldn''t put one in. It might mess with the computer. I put one on a older truck and my 99 allready has one. Is he right. The Ignition is different on all three trucks. And I would like to know the correct way to do it without messing anything up. Any help would be great.

 

I can't see how it would affect or could affect anything... your taking a signal that is already there and reading it...
Make sure your electrical connections are solid and are at good sources so that you don't introduce electrical noise into the system.. but a good well made tach should help eliminate that...

 

Get a schematic for your truck and see where the factory one would be connected and do the same thing.

 

Do u got a a smart phone ??? They sell this bluetooth obd2 for 20$ and a app and will do tac .trouble codes mpg so much stuff google (Bluetooth obd2) and shop around I seen one for 20$

 

I think if you check with some of the manufactures, they can answer your question.

One company, makes a Sunpro. I would think that instructions would come with any one that you would want to buy.

Good luck.

 

Thanks everyone. I want to use a tach I allready had on another truck. But I can see after in2pro comment that just to be safe I should go by a new one.

 

I put on on my 93 silverado, youll be fine
its a wire that you pigtail on to the coil and youll have a hot and ground