Hello everyone, so my stock tach was always stuck on 0, so being as 2 other stock gagues don't work i figured it was just fried so i bought a sunpro 5" tach.

I hooked the Red wire to the gagues fuse.
I hooked the white wire to the lights fuse
I hooked the black to the chasis

I then hooked the green to my MSD 6A box tach output, started it up it stuck on 0, i turned the dash lights on and the light for the tach was working even dimmed and brightened when turning the dimmer *** but the tach was staying at 0. I pressed the button that shows what rpm the shift light is set to and the needle moved to 5k(showing the shift light is set at 5k) i let go of the button it went back to 0.

I figured maybe it wont work with the MSD box for some reason so i hooked it up to the tach side of the distributor and it still didn't work no budge at all.

Here's the part that makes me wonder if it will ever work, my car is an 89 RS but the engine was swapped to a carbed 350 with a mechanical fuel pump and everything. So i'd assume my computer doesn't work so i cant just wire it into the computer tach wire(white i believe).

Here's the second part that seems problematic, whoever the PO was hooked the MSD 6A box to the distributor via magnetic pickup. So essentially the magnetic pickup is what i believe is used as the ignition, when we pulled off my coil(it was fried) we changed my cap and rotor too and it appeared my ignition module was completely bypassed. Could this be making the tach output for the distributor not work?

thank you for your feedback.

Edit: to add i believe my coil is on top of my distributor. I don't believe it's seperate.
Now that i messed with a green wire with a clip(looks like it went to the dist) my stock tach goes to about 500rpm when off 0's with key on and then bounces while starting then when the car is idling it stays out 0 with it hooked to the tach dist port, the tach output on msd and when unhooked lmao? the sunpro still doesn't move at all and before messing with the green wire my tach didn't move at all.

 

Work one item at a time, If you run a wire directly from the coil to the tachometer does the tachometer work?

 

I just recently did and on the 8 cyl option it does not, but on the 2 cyl opition(the distributor less option) it gets a signal but it's not at all right. At idle it's on 200rpm while accelerating it doesn't move then if I let off the gas it goes up like 100 rpm even at high rpm it doesn't go past like 700 rpm. So it's severely off if it's even responding to the rpm