Hi, I have an old style computerless HEI distributor, and my wiring is kinda hacked up at which point: but anyway I ran the green tach wire to the tach pin on the stock gauges and it doesn't move at all, ever. Is there like some tach secret? I am assuming it's the old HEI with the newer gauges, do I need like an interpreter box or something? Thanks in advance.

 

Your profile says 83 .....What car are we dealing with ?

90 -92 have known tacho problems
https://www.thirdgen.org/forums/elec...meter-fix.html

GM tacho signal is a tacho signal ; the tacho doesn't care so long as it is connected to the coil Neg terminal

What green wire?
The GM tacho signal wire is all white from the HEI TACH terminal to the gauge
The white wire / brown terminal in the pic

 

Thank you so much for answering, but anyways it's an 83, but it has a 91 dash and instruments. The green wire comes out of my distributor, I have two ports labeled Tach and Bat, the pigtail has a pink wire and a green one.

 

Should mention little things like that when asking a question

So you have non stock wiring
Do you have continuity on the green wire from the dist to the gauge connector?

 

Just went and checked it, it has continuity; I wasn't really sure whether to test AC or DC but it showed up like 5 amps AC or somewhere around there. Also it shocked me, so I know it has a current, haha.
And sorry I thought not stock wiring was implied with computerless.

 

Changing the dist doesn't require changing the tacho wiring, the stock white tacho wire in engine bay would be connected to the new dist.

Only way to identify the problem woUld be to connect a aftermarket tacho to the green wire and see if it works?
If it does you know your problem is with the cluster.

 

Well thank you so much you have been very insightful. Just some questions if the backlight for the tach is working is it safe to assume its 12v and ground are working? And just to clarify there is no reason a stock gauge shouldn't be able to read an aftermarket distributor, so since it is putting out a pulse I know that it works?

 

Depends
Back lighting is usually connected into the lighting circuit.
Tacho power is typically from the Ign

The way I see it the only way to narrow down the problem is by using a aftemarket tacho ?

 

So I tried it with a different tach and it still didn't move. But, I was reading about GMs having a tach filter? I actually found it on the firewall, should I run my tach wire through that? Or would that not cause it to not read at all?

 

Only one way to find out.
GM installed it for a reason for use with the stock tacho...........

 

So, it moves now, but... I feel like it reads like 1000rpm to high, could be more or less than that. For example when you floor the pedal just before it shifts the needle is buried in the dash. Is this that stock tach innacuracy I hear about? Seems a little extreme
Edit: Nevermind, I actaully read and learned something, Thank you so much for helping.